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 15 to 22.
It weighed about 10,000 tons, entered the atmosphere at a speed of 64,000 km/h and exploded over a city with a blast of 500 kilotons. But on 15 February 2013, we were lucky. The meteorite that showered pieces of rock over Chelyabinsk, Russia, was relatively small, at only about 17 metres wide. Although many people were injured by falling glass, the damage was nothing compared to what had happened in Siberia nearly one hundred years ago. Another relatively small object (approximately 50 metres in diameter) exploded in mid-air over a forest region, flattening about 80 million trees. If it had exploded over a city such as Moscow or London, millions of people would have been killed.
By a strange coincidence, the same day that the meteorite terrified the people of Chelyabinsk, another 50m-wide asteroid passed relatively close to Earth. Scientists were expecting that visit and know that the asteroid will return to fly close by us in 2046, but the Russian meteorite earlier in the day had been too small for anyone to spot.
Most scientists agree that comets and asteroids pose the biggest natural threat to human existence. It was probably a large asteroid or comet colliding with Earth which wiped out the dinosaurs about 65 million years ago. An enormous object, 10 to 16 km in diameter, struck the Yucatan region of Mexico with the force of 100 megatons. That is the equivalent of one Hiroshima bomb for every person alive on Earth today.
Many scientists, including the late Stephen Hawking, say that any comet or asteroid greater than 20 km in diameter that hits Earth will result in the complete destruction of complex life, including all animals and most plants. As we have seen, even a much smaller asteroid can cause great damage.
The Earth has been kept fairly safe for the last 65 million years by good fortune and the massive gravitational field of the planet Jupiter. Our cosmic guardian, with its stable circular orbit far from the sun, sweeps up and scatters away most of the dangerous comets and asteroids which might cross Earth’s orbit. After the Chelyabinsk meteorite, scientists are now monitoring potential hazards even more carefully but, as far as they know, there is no danger in the foreseeable future.
(Adapted from British Council Learning English Teens)
Which of the following statement is TRUE about the Russian meteorite?
A.It was too small to worry about.  
B.It came as a surprise.
C.It had been predicted by scientists.   
D.It will come close to Earth again in the future.

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Read the following passage  and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer to each for  the question  from 61 to 70.
            The Mayo Clinic in Rochester, Minnesota, where staff physicians practice a special integrated approach to patient care, is one of the lasgest medical facilities in the world. The clinic staff consists of a 12-member, committee-based of governors and 900 physicians and medical personnel whose records are updated by approximately 200 auxiliary personnel. About 800 resident doctors assist the full-time physicians as a phase of their training in medicine and surgery while they acquire their specializations. The Mayo approach to treatment has been hailed for its almost miraculous patient recovery rate.
            William Worral Mayo was born in Manchester, England, immigrated to the United States in 1845, and immediately began his medical training. In 1860, he took an active part in organizing the Minnesota Territory and accepted the position of an Army surgeon during a Sioux Indian outbreak. This appointment became a stepping stone for his advancement to the post of provost surgeon for the southern portion of the state in 1863. His personal dedication and courage became legendary when a cyclone struck Rochester, and he was placed in charge of an emergency hospital.
            William Worral Mayo provided crucial assistance to his sons in launching their team practice in 1889, while they were holding positions at St. Mary’s Hospital. William James became recognized for his surgical skill in gallstone, cancer, and abdominal operations. He and his brother, Charles Horace, founded the Mayo Graduate School of Medicine and donated $1.5 million to establish the foundation for contributions. Charles William, the son of Charles Horace Mayo, became a member of the board of governors at the Mayo Graduate School and an alternate delegate to the United Nations General Assembly before retiring from the clinic in 1963.
            William James Mayo presided in the American Medical Association and served in the Army military corps as a brigadier general in the medical reserve.  Charles Horace was a professor of surgery and a health officer of Rochester subsequent to serving in the armed forces between 1914 and 1918. The Mayo practice became known far and wide for its success in surgical procedures. In 1914, the practice moved into its own medical center, and today the number of patients equals approximately 280,000 per annum. Since the clinic opened in 1907, 4.5 million patients have been treated there.
In addition to their medical expertise, what common characteristics distinguished the careers of the Mayo brothers?
A.Funding of schools in minnesota
B.Positions on the board of directors
C.Military and political service
D. Donations for poor patients