Cho Cu tác dụng với H₂SO₄ đặc, nóng, sản phẩm được tạo thành từ H₂SO₄ là gì?

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California.

Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams.

Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward.

Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species.

The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species, males of most species are extremely colorful.

The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds.

Question 31: The word “minute” in the second paragraph is closest in meaning to _______.         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California.

Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams.

Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward.

Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species.

The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species, males of most species are extremely colorful.

The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds.

Question 32: The word "which" in the second paragraph refers to _______.         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California.

Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams.

Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward.

Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species.

The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species, males of most species are extremely colorful.

The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds.

Question 33: What does the author imply about the rate hummingbirds’ wings beat?         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California.

Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams.

Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward.

Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species.

The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species, males of most species are extremely colorful.

The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds.

Question 34: The author indicates that a hummingbird’s wings are different from those of other birds because         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California.

Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams.

Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward.

Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species.

The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species, males of most species are extremely colorful.

The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds.

Question 35: According to the passage, what causes the unique color and look of hummingbirds?         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

If we believe that clothing has to do with covering the body, and costume with the choice of a particular form of garment for a particular use, then we can say that clothing depend primarily on such physical conditions as climate, health, and textile manufacture, whereas costume reflect social factors such as religious beliefs, aesthetics, personal status, and the wish to be distinguished from or to emulate our fellows.

The ancient Greeks and the Chinese believed that we first covered our bodies for some physical reason such as protecting ourselves from the weather elements. Ethnologists and psychologists have invoked psychological reasons: modesty in the case of ancients, and taboo, magical influence and the desire to please for the moderns.

In early history, costume must have fulfilled a function beyond that of simple utility, perhaps through some magical significance, investing primitive man with the attributes of other creatures. Ornaments identified the wearer with animals, gods, heroes or other men. This identification remains symbolic in more sophisticated societies. We should bear in mind that the theater has its distant origins in sacred performances, and in all period children at play have worn disguises, so as to adapt gradually to adult life.

Costume helped inspire fear or impose authority. For a chieftain, costume embodied attributes expressing his power, while a warrior’s costume enhanced his physical superiority and suggested he was superhuman. In more recent times, professional or administrative costume has been devised to distinguish the wearer and express personal or delegated authority; this purpose is seen clearly in the judge’s robes and the police officer’s uniform. Costume denotes power, and since power is usually equated with wealth, costume came to be an expression of social caste and material prosperity. Military uniform denotes rank and is intended to intimidate, to protect the body and to express membership in a group. At the bottom of the scale, there are such compulsory costumes as the convict’s uniform. Finally, costume can possess a religious significance that combines various elements: an actual or symbolic identification with a god, the desire to express this in earthly life, and the desire to enhance the wearer’s position of respect.   

Question 36: The passage mainly discusses costume in terms of its _______.

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

If we believe that clothing has to do with covering the body, and costume with the choice of a particular form of garment for a particular use, then we can say that clothing depend primarily on such physical conditions as climate, health, and textile manufacture, whereas costume reflect social factors such as religious beliefs, aesthetics, personal status, and the wish to be distinguished from or to emulate our fellows.

The ancient Greeks and the Chinese believed that we first covered our bodies for some physical reason such as protecting ourselves from the weather elements. Ethnologists and psychologists have invoked psychological reasons: modesty in the case of ancients, and taboo, magical influence and the desire to please for the moderns.

In early history, costume must have fulfilled a function beyond that of simple utility, perhaps through some magical significance, investing primitive man with the attributes of other creatures. Ornaments identified the wearer with animals, gods, heroes or other men. This identification remains symbolic in more sophisticated societies. We should bear in mind that the theater has its distant origins in sacred performances, and in all period children at play have worn disguises, so as to adapt gradually to adult life.

Costume helped inspire fear or impose authority. For a chieftain, costume embodied attributes expressing his power, while a warrior’s costume enhanced his physical superiority and suggested he was superhuman. In more recent times, professional or administrative costume has been devised to distinguish the wearer and express personal or delegated authority; this purpose is seen clearly in the judge’s robes and the police officer’s uniform. Costume denotes power, and since power is usually equated with wealth, costume came to be an expression of social caste and material prosperity. Military uniform denotes rank and is intended to intimidate, to protect the body and to express membership in a group. At the bottom of the scale, there are such compulsory costumes as the convict’s uniform. Finally, costume can possess a religious significance that combines various elements: an actual or symbolic identification with a god, the desire to express this in earthly life, and the desire to enhance the wearer’s position of respect.      

Question 37: What is the purpose of the paragraph 1?             

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

If we believe that clothing has to do with covering the body, and costume with the choice of a particular form of garment for a particular use, then we can say that clothing depend primarily on such physical conditions as climate, health, and textile manufacture, whereas costume reflect social factors such as religious beliefs, aesthetics, personal status, and the wish to be distinguished from or to emulate our fellows.

The ancient Greeks and the Chinese believed that we first covered our bodies for some physical reason such as protecting ourselves from the weather elements. Ethnologists and psychologists have invoked psychological reasons: modesty in the case of ancients, and taboo, magical influence and the desire to please for the moderns.

In early history, costume must have fulfilled a function beyond that of simple utility, perhaps through some magical significance, investing primitive man with the attributes of other creatures. Ornaments identified the wearer with animals, gods, heroes or other men. This identification remains symbolic in more sophisticated societies. We should bear in mind that the theater has its distant origins in sacred performances, and in all period children at play have worn disguises, so as to adapt gradually to adult life.

Costume helped inspire fear or impose authority. For a chieftain, costume embodied attributes expressing his power, while a warrior’s costume enhanced his physical superiority and suggested he was superhuman. In more recent times, professional or administrative costume has been devised to distinguish the wearer and express personal or delegated authority; this purpose is seen clearly in the judge’s robes and the police officer’s uniform. Costume denotes power, and since power is usually equated with wealth, costume came to be an expression of social caste and material prosperity. Military uniform denotes rank and is intended to intimidate, to protect the body and to express membership in a group. At the bottom of the scale, there are such compulsory costumes as the convict’s uniform. Finally, costume can possess a religious significance that combines various elements: an actual or symbolic identification with a god, the desire to express this in earthly life, and the desire to enhance the wearer’s position of respect.

Question 38: Psychological reasons for wearing garments include _______.         

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

If we believe that clothing has to do with covering the body, and costume with the choice of a particular form of garment for a particular use, then we can say that clothing depend primarily on such physical conditions as climate, health, and textile manufacture, whereas costume reflect social factors such as religious beliefs, aesthetics, personal status, and the wish to be distinguished from or to emulate our fellows.

The ancient Greeks and the Chinese believed that we first covered our bodies for some physical reason such as protecting ourselves from the weather elements. Ethnologists and psychologists have invoked psychological reasons: modesty in the case of ancients, and taboo, magical influence and the desire to please for the moderns.

In early history, costume must have fulfilled a function beyond that of simple utility, perhaps through some magical significance, investing primitive man with the attributes of other creatures. Ornaments identified the wearer with animals, gods, heroes or other men. This identification remains symbolic in more sophisticated societies. We should bear in mind that the theater has its distant origins in sacred performances, and in all period children at play have worn disguises, so as to adapt gradually to adult life.

Costume helped inspire fear or impose authority. For a chieftain, costume embodied attributes expressing his power, while a warrior’s costume enhanced his physical superiority and suggested he was superhuman. In more recent times, professional or administrative costume has been devised to distinguish the wearer and express personal or delegated authority; this purpose is seen clearly in the judge’s robes and the police officer’s uniform. Costume denotes power, and since power is usually equated with wealth, costume came to be an expression of social caste and material prosperity. Military uniform denotes rank and is intended to intimidate, to protect the body and to express membership in a group. At the bottom of the scale, there are such compulsory costumes as the convict’s uniform. Finally, costume can possess a religious significance that combines various elements: an actual or symbolic identification with a god, the desire to express this in earthly life, and the desire to enhance the wearer’s position of respect.

Question 39: The word “Ornaments” in paragraph 3 is closet in meaning to _______.         

Because writing has become so important in our culture, we sometimes think of it as more real than speech. A little thought, however, will show why speech is primary and writing secondary to language. Human beings have been writing (as far as we can tell from surviving evidence) for at least 5000 years; but they have been talking for much longer, doubtless ever since there have been human beings.

When writing did develop, it was derived from and represented speech, although imperfectly. Even today there are spoken languages that have no written form. Furthermore, we all learn to talk well before we learn to write, any human child who is not severely handicapped physically or mentally will learn to talk: a normal human being cannot be prevented from doing so. On the other hand, it takes a special effort to learn to write. In the past many intelligent and useful members of society did not acquire the skill, and even today many who speak languages with writing systems never learn to read or write, while some who learn the rudiments of those skills do so only imperfectly.

To affirm the primacy of speech over writing is not, however, to disparage the latter. One advantage writing has over speech is that it is more permanent and makes possible the records that any civilization must have. Thus, if speaking makes us human, writing makes us civilized.

Question: Learning to write is ______.