What _______ can be drawn from the experiment of two American physicists, Clinton Davisson and Lester Germer?

A. conclusion

B. attention

C. contrast

D. inference

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.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

Recreational diving ______.

A. requires more equipment than technical diving 

B. are taken up by many people for leisure and entertainment

C. needs no equipment

D. requires more experience than technical diving

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 38 to 42.

         There are many superstitions in Britain, but one of the most (38)_______held is that it is unlucky to walk under a ladder even if it means (39)______the pavement into a busy street! If you must pass under a

ladder, you can avoid bad luck by crossing your fingers and keeping them crossed until you have seen a dog. Alternatively, you may lick your finger and make a cross on the toe of your shoe, and not look again at the shoe until the mark has dried.

        Another common superstition is that it is unlucky to open an umbrella in the house - it will either bring misfortune to the person who opened it or to the whole (40)______. Anyone opening an umbrella in

the fine weather is unpopular, as it inevitably brings rain!

        The number 13 is said to be unlucky for some, and when the 13th day of the month (41)_______on a Friday, anyone wishing to avoid a bad event had better stay indoors. The worst misfortune that can happen to a person is caused by breaking a mirror, as it brings seven years of bad luck! The superstition is supposed to be originated in ancient times, when mirrors were considered to be tools of the gods.

        Black cats are generally considered lucky in Britain, even though they are associated with witchcraft. It is especially lucky if a black cat crosses your path - although in America the exact opposite belief prevails.

        Finally, a commonly held superstition is that of touching wood (42)________luck. This measure is most often taken if you think you have said something that is tempting fate, such as “My car has never broken down, touch wood?”

Điền vào ô 40.

A. house

B. household

C. home

D. member

Trong hình hộp ABCD.A’B’C’D’ có tất cả các cạnh đều bằng nhau. Trong các mệnh đề sau, mệnh đề nào sai?

A.  B B ' ⊥ B D

B.  A ' C ' ⊥ B ​ D

C.  A ' B ⊥ D C '

D.  B C ' ⊥ A ' ​ D