a) Tìm GTLN của biểu thức B = \(-x^2+6x+5\)

b)Tìm GTNN của biểu thức A = \(x^2+2x+6\)

Choose the sentence which is closest in meaning to the one

1. The police let him leave after they had questioned.

A. He was let to leave after he had his questions.

B. He was allowed not to leave after being questioned by the police.

C. He was released after being questioned by the police.

D. The police would permit him to leave provided he was questioned

2. It was kind of Jane to send me flowers when I was sick.

A. I was kind enough to send Jane flowers.

B. I appreciate Jane sending me flowers when I was ill.

C. Jane was ill so I sent her flowers.

D. When I was ill, I received some flowers from Jane.

3. Although Mr. Pike was seriously sick, he still composed nice pieces of music.

A. Mr. Pike's pieces of music were very serious.

B. Mr. Pike did not compose any nice piece of music because he was sick.

C. Despite his sickness, Mr. Pike still composed nice pieces of music.

D. Mr. Pike was too sick to compose music.

4. Jack is afraid he'll gain weight if he stops smoking.

A. Jack is afraid he'll become fat if he quits smoking.

B. Jack does not realize the dangers of smoking.

C. Jack is afraid of giving up smoking.

D. Jack is worried he'll put on weight of he cuts down on smoking.

5. The error on my taxes was made by my accountant.

A. My tax accountant found the mistake that I made.

B. I made an error because I did not have a tax accountant.

C. Tax accountants always make errors.

D. My accountant made a mistake. given

Choose the correct phrase or clause to finish these sentences.

1. Skimming along the surface of the ocean or rising from its depths like delicate balloons, __________ to their aquatic habitat.

A. the perfect adaptation of jellyfish

B. jellyfish are perfectly adapted

C. jellyfish are adapted to perfection

D. the adaptation is perfect for jellyfish

2. __________ around, it gives us vital information about our environment.

A. The sounds are heard

B. That we hear the sounds

C. Hearing the sounds

D. Whatever the sounds are heard

3. Beginning in the Middle Ages, composers of Western music used a system of notating their compositions __________.

A. yet they would be performed by musicians

B. that be performed by musicians

C. when performed by musicians

D. so they could be performed by musicians

4. Civil Rights are the freedoms and rights __________ as a member of a community, state, or nation.

A. may have a person

B. that have a person

C. a person may have

D. and a person may have

5. During the late fifteenth century, __________ had professions in the fields of arts and crafts.

A. only a few of the native societies of America

B. only few of the native societies of America

C. few but only of the native American societies

D. a few only of the native American societies

Choose the word or phrase that best replaces the underlined in each line of the sentences.

1. All at once, the sky became dark and it started to rain.

A. At times B. Suddenly C. Occasionally D. Immediately ​

2. I was on my own a lot when I went to England to study.

A. free B. sad C. sick D. alone

3. Every house in this street has been demolished.

A. explored B. torn down C. removed D. torn up

4. I submitted an application, but the committee turned it down.

A. rejected it

B. refused to take it

C. threw it away

D. made it shorter

5. She showed considerable talent for getting what she wanted.

A. inability B. capability C. persistence D. qualification

6. A free trade agreement would be advantageous to both countries.

A. agreeable B. beneficial C. preferential D. initial

7. He sounded panic-stricken on the phone.

A. happy B. troubled C. terrified D. disappointed

8. The council advocated banning cars in the city centre.

A. supported B. voted against C. asked for D. issued

9. His constant boasting irritated her.

A. annoyed B. excited C. petrified D. hurt

10. Despite her abilities she has been repeatedly overlooked for promotion.

A. overdid B. noticed C. requested D. ignored

Read the following passage and choose the correct answer to each question.

Very few people in the modern world obtain their food supply by hunting and gathering in the natural environment surrounding their homes. This method of harvesting from nature's provision is the oldest known subsistence strategy, and has been practised for at least the last two million years. It was, indeed, the only way to obtain food until rudimentary farming and the domestication of animals were introduced about 10,000 years ago.

​Because hunter-gatherers have fared poorly in comparison with their agricultural cousins, their numbers have dwindled, and they have been forced to live in marginal environments such as deserts, forests, or arctic wastelands. In higher latitudes, the shorter growing season has restricted the availability of plant life. Such conditions have caused a greater dependence on hunting and along the coasts and waterways, on fishing. The abundance of vegetation in the lower latitudes of the tropics, on the other hand, has provided a greater opportunity for gathering a variety of plants. In short, the environmental differences have restricted the diet and have limited possibilities for the development of subsistence societies. Contemporary hunter-gatherers may help us understand our prehistoric ancestors. We know from observation of modern hunter-gatherers in both Africa and Alaska that a society based on hunting and gathering must be very mobile. While the entire community camps in a central location, a smaller party harvests the food within a reasonable distance from the camp. When the food in the area is exhausted, the community moves on to exploit another site. We also notice a seasonal migration pattern evolving for most hunter-gatherers, along with a strict division of labour between the sexes. These patterns of behaviour may be similar to those practised by mankind during the Paleolithic Period.

1. With which of the following topics is the passage primarily concerned?

A. The Paleolithic period

B. Subsistence farming

C.Hunter-gatherers

D. Marginal environments

2. Which is the oldest subsistence strategy?

A. Migrating

B. Domesticating animals

C. Farming

D. Hunting and gathering

3. When was hunting and gathering introduced?

A. 1,000,000 years ago

B. 2,000,000 years ago

C. 10,000 years ago

D. 2,000 years ago

4. What conditions exist in lower latitudes?

A. Greater dependence on hunting.

B. More coasts and waterways for fishing.

C. A shorter growing season.

D. A large variety of plant life.

5. How can we know more about the hunter-gatherers of prehistoric times?

A. By studying the remains of their camp sites.

B. By studying similar contemporary societies.

C. By studying the prehistoric environment.

D. By practising hunting and gathering.