Tập nghiệm của bất phương trình 16^x < 3.4^x + 4 là:

Tập nghiệm của hệ bất phương trình  là:

Giá trị của biểu thức log₉(9 + 4) + log₉(9 - 4) + log₉81 bằng:

Với x > 0, đạo hàm của hàm số  bằng :

Hàm số nào sau đây nghịch biến trên R?

Tập nghiệm của bất phương trình 16^x < 3.4^x + 4 là:

Số nghiệm của phương trình (x² - x - 6)log₂(x² - 9) = 0 là:

Phương trình log(1 - 2x) - 2logx = 1 - log(2 - 5x) có nghiệm là:

Tập nghiệm của phương trình  là:

Tập nghiệm của phương trình log₄[x(4 - x)] = 1 là:

Nghiệm của hệ phương trình  là:

Phương trình 7.3^x+1 — 5^x+2 = 3^x+4 — 5^x+3 có nghiệm là giá trị nào sau đây?

Mệnh đề nào sau đây là đúng?

Biểu thức 2^-(2x+1) - 2^-(2x-1) + 2^-2x bằng :

Tập nghiệm của bất phương trình  là:

Các giá trị của a để  là:

Tập nghiệm của phương trình  là:

Cho hàm số f(x) = 2^x. Ta có f(a + 1) - f(a) bằng:

Giá trị của   là kết quả nào sau đây?

Tổng các nghiệm của phương trình 3^2x+2 - 3^x+3 - 3^x + 3 = 0 là:

Tập nghiệm của bất phương trình 27^x + 12^x ≤ 2. 8^x là: 

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.

Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes harm ecosystems. If there is too ___26__ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that feed on it may also die or move away. Some changes are good for ecosystems. Some pine forests need fire for the pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds ___27___. Polluting the air, soil, and water can harm ecosystems. Building ___28___ on rivers for electric power and irrigation can harm ecosystems around the rivers. Bulldozing wetlands and cutting down ___29___ destroy ecosystems. Ecologists are working with companies and governments to find better ways of catching fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people ___30___ causing harm to ecosystems.

Question 29:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.

Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes harm ecosystems. If there is too ___26__ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that feed on it may also die or move away. Some changes are good for ecosystems. Some pine forests need fire for the pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds ___27___. Polluting the air, soil, and water can harm ecosystems. Building ___28___ on rivers for electric power and irrigation can harm ecosystems around the rivers. Bulldozing wetlands and cutting down ___29___ destroy ecosystems. Ecologists are working with companies and governments to find better ways of catching fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people ___30___ causing harm to ecosystems.

Question 27:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.

Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes harm ecosystems. If there is too ___26__ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that feed on it may also die or move away. Some changes are good for ecosystems. Some pine forests need fire for the pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds ___27___. Polluting the air, soil, and water can harm ecosystems. Building ___28___ on rivers for electric power and irrigation can harm ecosystems around the rivers. Bulldozing wetlands and cutting down ___29___ destroy ecosystems. Ecologists are working with companies and governments to find better ways of catching fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people ___30___ causing harm to ecosystems.

Question 26:

Question 31

THOMAS EDISON

On the night of 21 October 1931, millions of Americans took part in a coast-to-coast ceremony to commemorate the passing of a great man. Lights (31) _______ in homes and offices from New York to California. The ceremony marked the death of arguably the most important inventor of all time: Thomas Edison.

Few inventors have (32) _______ such an impact on everyday life, and many of his inventions played a crucial role in the development of modern technology. One should never (33) _______ how revolutionary some of Edison’s inventions were.

In many ways, Edison is the perfect example of an inventor - that is, not just someone who dreams up clever gadgets, but someone whose products transform the lives of millions. He possessed the key characteristics that an inventor needs to (34) _______ a success of inventions, notably sheer determination. Edison famously tried thousands of materials while working on a new type of battery, reacting to failure by cheerfully announcing to his colleagues: 'Well, (35) _______ we know 8,000 things that don’t work.’ Knowing when to take no notice of experts is also important. Edison’s proposal for electric lighting circuitry was received with total disbelief by eminent scientists, until he lit up whole streets with his lights.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks from 46 to 50:

 Here are tips that help succeed in your job interview: Always arrive early. If you do not know (46) _________ the organization is located, call for exact directions (47) ____________ advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (48) _________ to everyone as soon as you walk in the door. Wear a professional business suit. This point should be emphasized enough. First (49) ____________ are extremely important in the interview process. Women should (50)_________ wearing too much jewelry or make up. Men should avoid flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. Regardless, you can never be overdressed if you are wearing a tailored suit.   

Question 46:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks from 46 to 50:

 Here are tips that help succeed in your job interview: Always arrive early. If you do not know (46) _________ the organization is located, call for exact directions (47) ____________ advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (48) _________ to everyone as soon as you walk in the door. Wear a professional business suit. This point should be emphasized enough. First (49) ____________ are extremely important in the interview process. Women should (50)_________ wearing too much jewelry or make up. Men should avoid flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. Regardless, you can never be overdressed if you are wearing a tailored suit.   

Question 50:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks from 46 to 50:

 Here are tips that help succeed in your job interview: Always arrive early. If you do not know (46) _________ the organization is located, call for exact directions (47) ____________ advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (48) _________ to everyone as soon as you walk in the door. Wear a professional business suit. This point should be emphasized enough. First (49) ____________ are extremely important in the interview process. Women should (50)_________ wearing too much jewelry or make up. Men should avoid flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. Regardless, you can never be overdressed if you are wearing a tailored suit.   

Question 49:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks from 46 to 50:

 Here are tips that help succeed in your job interview: Always arrive early. If you do not know (46) _________ the organization is located, call for exact directions (47) ____________ advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (48) _________ to everyone as soon as you walk in the door. Wear a professional business suit. This point should be emphasized enough. First (49) ____________ are extremely important in the interview process. Women should (50)_________ wearing too much jewelry or make up. Men should avoid flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. Regardless, you can never be overdressed if you are wearing a tailored suit.   

Question 48:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks from 46 to 50:

 Here are tips that help succeed in your job interview: Always arrive early. If you do not know (46) _________ the organization is located, call for exact directions (47) ____________ advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (48) _________ to everyone as soon as you walk in the door. Wear a professional business suit. This point should be emphasized enough. First (49) ____________ are extremely important in the interview process. Women should (50)_________ wearing too much jewelry or make up. Men should avoid flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. Regardless, you can never be overdressed if you are wearing a tailored suit.   

Question 47:

Question 34

THOMAS EDISON

On the night of 21 October 1931, millions of Americans took part in a coast-to-coast ceremony to commemorate the passing of a great man. Lights (31) _______ in homes and offices from New York to California. The ceremony marked the death of arguably the most important inventor of all time: Thomas Edison. Few inventors have (32) _______ such an impact on everyday life, and many of his inventions played a crucial role in the development of modern technology. One should never (33) _______ how revolutionary some of Edison’s inventions were. In many ways, Edison is the perfect example of an inventor - that is, not just someone who dreams up clever gadgets, but someone whose products transform the lives of millions. He possessed the key characteristics that an inventor needs to (34) _______ a success of inventions, notably sheer determination. Edison famously tried thousands of materials while working on a new type of battery, reacting to failure by cheerfully announcing to his colleagues: 'Well, (35) _______ we know 8,000 things that don’t work.’ Knowing when to take no notice of experts is also important. Edison’s proposal for electric lighting circuitry was received with total disbelief by eminent scientists, until he lit up whole streets with his lights. .