Đề thi đại học môn Tiếng Anh khối A1 năm 2014 - Mã đề 163

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

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 26 to 35. 

A radio telescope is a radio receiver that "sees" radio waves. Unlike a normal telescope, which sees light, a radio telescope is used primarily in the are a of astronomy because it can detect radio waves that are emitted by celestial objects. Such objects in space, also called radio objects, can be things such as hot gas, electrons, and wavelengths given off by different atoms and molecules.

The first radio telescope was invented by Grote  Reber  in 1937. He was an American who graduated with a degree in engineering. He went on to work as an amateur radio operator and later decided to try to build his own radio telescope in his backyard. Reber's  first two radio receivers failed to pick up any signals from outer space, but in 1938, his third radio telescope successfully picked up radio waves from A radio telescope consists of a large parabolic-shaped dish antenna or a combination of two or more. The significance of the parabolic shape allows for the incoming radio waves to be concentrated on one focal point, allowing the signals to be picked up as strongly as possible. A larger dish means that more signals can be received and focalized.

In the late 1950s and early 1960s, the largest radio telescope of the time was invented with a seventy-six meter telescope although larger telescopes have been made since then. The largest current radio telescope in the world is the RATAN-600 in Russia, whose diameter  is 576 meters. It has provided valuable feedback of the sun's radio wavelengths  and atmosphere. The largest radio telescope in Europe is a 100-meter diameter  telescope in Germany, and the largest radio telescope in the United States is the Big Ear in the state of Ohio. The largest array of telescopes is the Giant Metrewave Radio Telescope in India.

Radio telescopes have provided scientists with valuable information about our universe. One of the most  important functions of radio telescopes is their ability to allow scientists to track different space probes, the  unmanned space missions in outer space. Radio telescopes allow for the travel of space probes into places like the surface of Mars that are too dangerous for men to explore. With out radio wave technology, scientists would not know much of what inhabits the universe nor would they be able to see it. Radio waves are our eyes and ears in outer space. 

Read the following passage and mark the letter A, B,C, or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks from 36 to 45.

Why is it that many teenagers have the energy to play computer games until late at night but can't find the energy to get out of bed (36)_______ for school? According to a new report, today's generation of children are in danger of getting so (37)________ sleep that they  are putting their mental and physical health at (38)________. Adults can easily survive on seven to eight hours' sleep a night, (39)________ teenagers  require nine or ten hours. According to medical experts, one in five youngsters(40)_________ anything between two and five hours' sleep a night less than their parents did at their age. This (41)_________ serious questions about whether lack of sleep is affecting children's ability to

concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (42)_________. Research has shown that losing as little as half an hour's sleep a night can have profound effects (43)________ how children perform the next day. A good night's sleep is also crucial for teenagers because it is while they are asleep (44)________ they release a hormone that is essential for their 'growth spurt' (the period during teenage years when the body grows at a rapid rate). It's true that they can, to some (45)________, catch up on sleep at weekends, but that won't help them when they are dropping off to sleep in class on a Friday afternoon. 

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions. 

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 51 to 60. 

The ability to conduct electricity is one of the key properties of a metal. Other solid materials such as silicon can conduct electricity but only effectively at certain temperatures. Also, some substances such as salt (sodium chloride) can conduct when molten or when dissolved in water. The ability of metals to conduct electricity is due to how their atoms bond together. In order to bond together the metal atoms lose at least one of their outermost electrons. This leaves the metal atoms with a positive charge and they are now strictly ions. The lost electrons are free to move in what is known as a sea of electrons. Since the electrons are negatively charged they attract the ions and this is what keeps the structure together.

An electric current is a flow of charge and since the electrons in the sea of electrons are free to move they can be made to flow in one direction when a source of electrical energy such as a battery is connected to the metal. Hence we have an electric current flowing through the wire, and this is what makes metals such good conductors of electricity. The only other common solid conducting material that pencil users are likely to encounter is graphite (what the ‘lead’ of a pencil is made from). Graphite is a form of carbon and again the carbon atoms bond in such a way that there is a sea of electrons that can be made to flow as an electric current. Likewise, if we have an ionic substance like salt we can make the electrically charged ions flow to create a current but only when those ions are free to move, either when the substance is a liquid or dissolved in water. In its solid state an ionic substance like salt cannot conduct electricity as its charged ions cannot flow.

Electrical insulators are substances that cannot conduct electricity well either, because they contain no charged particles or any charged particles they might contain do not flow easily. Water itself is a poor conductor of electricity as it does not contain a significant amount of fully charged particles (the ends of a water molecule are partly charged but overall the molecule is neutral). However, most water we encounter does contain dissolved charged particles, so it will be more conductive than pure water. Many of the problems that occur when touching electrical devices with wet hands result from the ever-present salt that is left on our skin through perspiration and it dissolves in the water to make it more conductive

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 of the primary stress in each of the following questions. 

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs  correction in each of the following questions. 

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is CLOSEST in meaning to the sentence given in each of the following questions.