Cho $a>1$ . Mệnh đề nào sau đây đúng?

Từ chữ số và lập được bao nhiêu số tự nhiên có chữ số sao cho không có chữ số đứng cạnh nhau?  

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

A number of factors related to the voice reveal the personality of the speaker.

The first is the broad area of communication, which includes imparting information by use of language, communicating with a group or an individual and specialized communication through performance. A person conveys thoughts and ideas through choice of words, by a tone of voice that is pleasant or unpleasant, gentle or harsh, by the rhythm that is inherent within the language itself, and by speech rhythms that are flowing and regular or uneven and hesitant, and finally, by the pitch and melody of the utterance. When speaking before a group, a person's tone may indicate uncertainty or fright, confidence or calm. At interpersonal levels, the tone may reflect ideas and feelings over and above the words chosen, or may belie them. Here the participant’s tone can consciously or unconsciously reflect intuitive sympathy or antipathy, lack of concern or interest, fatigue, anxiety, enthusiasm or excitement, all of which are usually discernible by the acute listener. Public performance is a manner of communication that is highly specialized with its own techniques for obtaining effects by voice and/or gesture. The motivation derived from the text, and in the case of singing, the music, in combination with the performer's skills, personality, and ability to create empathy will determine the success of artistic, political, or pedagogic communication.

Second, the voice gives psychological clues to a person's self-image, perception of others, and emotional health. Self-image can be indicated by a tone of voice that is confident, pretentious, shy, aggressive, outgoing, or exuberant, to name only a few personality traits. Also the sound may give a clue to the facade or mask of that person, for example, a shy person hiding behind an overconfident front. How a speaker perceives the listener's receptiveness, interest, or sympathy in any given conversation can drastically alter the tone of presentation, by encouraging or discouraging the speaker. Emotional health is evidenced in the voice by free and melodic sounds of the happy, by constricted and harsh sound of the angry, and by dull and lethargic qualities of the depressed.  

Question: According to the passage, an exuberant tone of voice may be an indication of a person's………         

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

A number of factors related to the voice reveal the personality of the speaker.

The first is the broad area of communication, which includes imparting information by use of language, communicating with a group or an individual and specialized communication through performance. A person conveys thoughts and ideas through choice of words, by a tone of voice that is pleasant or unpleasant, gentle or harsh, by the rhythm that is inherent within the language itself, and by speech rhythms that are flowing and regular or uneven and hesitant, and finally, by the pitch and melody of the utterance. When speaking before a group, a person's tone may indicate uncertainty or fright, confidence or calm. At interpersonal levels, the tone may reflect ideas and feelings over and above the words chosen, or may belie them. Here the participant’s tone can consciously or unconsciously reflect intuitive sympathy or antipathy, lack of concern or interest, fatigue, anxiety, enthusiasm or excitement, all of which are usually discernible by the acute listener. Public performance is a manner of communication that is highly specialized with its own techniques for obtaining effects by voice and/or gesture. The motivation derived from the text, and in the case of singing, the music, in combination with the performer's skills, personality, and ability to create empathy will determine the success of artistic, political, or pedagogic communication.

Second, the voice gives psychological clues to a person's self-image, perception of others, and emotional health. Self-image can be indicated by a tone of voice that is confident, pretentious, shy, aggressive, outgoing, or exuberant, to name only a few personality traits. Also the sound may give a clue to the facade or mask of that person, for example, a shy person hiding behind an overconfident front. How a speaker perceives the listener's receptiveness, interest, or sympathy in any given conversation can drastically alter the tone of presentation, by encouraging or discouraging the speaker. Emotional health is evidenced in the voice by free and melodic sounds of the happy, by constricted and harsh sound of the angry, and by dull and lethargic qualities of the depressed.

Question: According to the passage, what does a constricted and harsh voice indicate?         

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

The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.   

Question: What topic is this passage primarily concerned?         

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

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority.

Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing. Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population. Finally, it is worth noting that the terms ''standard", "colloquial”, and "slang” exist only as abstract levels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.

Question: The word "appropriate” is closest in meaning to _______.  

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

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority.

Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing. Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population. Finally, it is worth noting that the terms ''standard", "colloquial”, and "slang” exist only as abstract levels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.

Question: Which of the following is the main topic of the passage?

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

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority.

Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing. Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population. Finally, it is worth noting that the terms ''standard", "colloquial”, and "slang” exist only as abstract levels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.

Question: The word "them" refers to _______.  

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

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority.

Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing. Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population. Finally, it is worth noting that the terms ''standard", "colloquial”, and "slang” exist only as abstract levels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.

Question: The word "obscurity" could best be replaced by _______.  

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

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority.

Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing. Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population. Finally, it is worth noting that the terms ''standard", "colloquial”, and "slang” exist only as abstract levels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.

Question: The author mentions all of the following as requirements for slang expressions to be created EXCEPT _______.         

Có bao nhiêu số tự nhiên có tám chữ số trong đó có ba chữ số , không có hai chữ số nào đứng cạnh nhau và các chữ số khác chỉ xuất hiện nhiều nhất một lần?