Chứng minh rằng với mọi số nguyên dương n thì:

A = 3ⁿ⁺³ + 3ⁿ⁺¹ + 2ⁿ⁺² + 2ⁿ⁺¹ chia hết cho 6

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

FIRST TIME IN THE AIR

When John Mills was going to fly in an airplane for the first time, he was frightened. He did not like the idea of being thousands of feet up in the air. "I also didn't like the fact that I wouldn't be in control," says John.

"I'm a terrible passenger in the car. When somebody else is driving, I tell them what to so. It drives everybody crazy."

However John couldn't avoid flying any longer. It was the only way he could visit his grandchildren in Canada.

"I had made up my mind that I was going to do it, I couldn't let my son, his wife and their three children travel all the way here to visit me. It would be so expensive for them and I know Tom's business isn't doing so well at the moment - it would also be tiring for the children - it's a nine-hour flight!" he says.

To get ready for the flight John did lots of reading about airplanes. When he booked his seat, he was told that he would be flying on a Boeing 747, which is better known as a jumbo jet. "I needed to know as much as possible before getting in that plane. I suppose it was a way of making myself feel better. The Boeing 747 is the largest passenger aircraft in the world at the moment. The first one flew on February 9th 1969 in the USA. It can carry up to 524 passengers and 3.400 pieces of luggage. The fuel for airplanes is kept in the wings and the 747's wings are so big that they can carry enough fuel for an average car to be able to travel 16,000 kilometers a year for 70 years. Isn't that unbelievable? Even though I had discovered all this very interesting information about the jumbo, when I saw it for the first time, just before I was going to travel to Canada, I still couldn't believe that something so enormous was going to get up in the air and fly. I was even more impressed when I saw how big it was inside with hundreds of people!"

The biggest surprise of all for John was the flight itself. "The take-off itself was much smoother than I expected although I was still quite scared until we were in the air. In the end, I managed to relax, enjoy the food and watch one of the movies and the view from the window was spectacular. I even managed to sleep for a while!

"Of course," continues John, "the best reward of all was when I arrived in Canada and saw my son and his family, particularly my beautiful grandchildren. Suddenly, I felt so silly about all the years when I couldn't even think of getting on a plane. I had let my fear of living stop me from seeing the people I love most in the world. I can visit my son and family as often as I like now!"

Why did John Mills fly in an airplane?

A. He wanted to go on holiday

B. He wanted to try it.

C. He wanted to see his family

D. He had to travel on 

Read the following passage and blacken the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

        The history of clinical nutrition, or the study of the relationship between health and how the body takes in and utilizes food substances, can be divided into four distinct eras: the first began in the nineteenth century and extended into the early twentieth century when it was recognized for the first time that food contained constituents that were essential for human function and that different foods provided different amounts of these essential agents. Near the end of this era, research studies demonstrated that rapid weight loss was associated with nitrogen imbalance and could only be rectified by providing adequate dietary protein associated with certain foods.

       The second era was initiated in the early decades of the twentieth century and might be called “the vitamin period.” Vitamins came to be recognized in foods, and deficiency syndromes were described. As vitamins became recognized as essential food constituents necessary for health, it became tempting to suggest that every disease and condition for which there had been no previous effective treatment might be responsive to vitamin therapy. At that point in time, medical schools started to become more interested in having their curricula integrate nutritional concepts into the basic sciences. Much of the focus of this education was on the recognition of deficiency symptoms. Herein lay the beginning of what ultimately turned from ignorance to denial of the value of nutritional therapies in medicine. Reckless claims were made for effects of vitamins that went far beyond what could actually be achieved from the use of them.

        In the third era of nutritional history in the early 1950's to mid-1960's, vitamin therapy began to fall into disrepute. Concomitant with this, nutrition education in medical schools also became less popular. It was just a decade before this that many drug companies had found their vitamin sales skyrocketing and were quick to supply practicing physicians with generous samples of vitamins and literature extolling the virtue of supplementation for a variety of health-related conditions. Expectations as to the success of vitamins in disease control were exaggerated. As is known in retrospect, vitamin and mineral therapies are much less effective when applied to health-crisis conditions than when applied to long-term problems of under nutrition that lead to chronic health problems.

It can be inferred from the passage that which of the following discoveries was made during the first era in the history of nutrition?

A. Protein was recognized as an essential component of diet.

B. Vitamins were synthesized from foods.

C. Effective techniques of weight loss were determined.

D. Certain foods were found to be harmful to good health.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 35.

For hundreds of years, giving flowers have been a social means of communication. In the United States, flowers are often given during rites of passage, for commemorating special occasions or as a heartfelt gift between loved ones and friends. Flower gifting also occurs in most countries around the world. However, the meanings and traditions often vary.

While students traditionally gave their favorite teacher an apple in past years, in China, teachers are given flowers. Peonies are by far the flower most often given in China. They are also quite popularly used for weddings. Strangely, potted plants are not considered a pleasant gift among Asian cultures. The people believe that like a plant confined by a pot, the gift symbolizes a binding or restriction.

In Russia, in lieu of giving birthday presents, the guest of honor receives a single flower or an unwrapped bouquet. Floral arrangements or baskets are not given. Russians celebrate a holiday known as Woman's Day. Traditional gifts include red roses, hyacinths or tulips. When there is a funeral or other occasion where someone wishes to express sympathy, carnations, lilies or roses are given in circular configurations, which signify the transition of birth, life and death to rebirth. In this instance, the color of choice is commonly yellow. For joyous occasions, arrangements and bouquets generally contain an odd number of flowers.

In the times of ancient Rome, brides carried flowers to scare away evil spirits and encourage fertility. The Dutch believed that flowers were food for the soul. When invited to someone's home in Great Britain, it is tradition to bring a gift of flowers. All types are acceptable except white lilies, which are usually seen at funerals. Unlike the United States, red roses are a symbol of love. Flowers are generally gifted in odd numbered increments regardless of the occasion. However, the Brits also have superstitions regarding the number 13, so the number is avoided.

In the southern region of the continent, flowers are traditionally given during Christmas. Egyptians are much more conservative and restrict flower gifting to funerals and weddings. While certain flowers may have significant meanings for some, flowers in Las Vegas and across the United States flowers are an accepted gift for any reason desired.

In which country should not people bring white lilies to other houses?

A. China

B. Russia

C. Great Britain

D. United States

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position ofprimary stress in each of the following questions.

A. magnificent

B. miraculous

C. superior

D. electronic

Kết quả của phép tính: 35 × 11 = …. ?

A. 3535

B. 385

C. 835

D. 538

Hai đội xe vận chuyển dưa hấu ra thành phố, đội xe thứ nhất có 8 xe, đội xe thứ hai có 5 xe, mỗi xe chở 1250kg dưa hấu. Hỏi cả hai đội xe chở được tất cả bao nhiêu ki-lô-gam dưa hấu? (giải bằng 2 cách)