[单项选择]Many scientists today are convinced that life exists elsewhere in the universe—life probably much like that on our own planet. They reason in the following way.
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere, a larger one would hold too much of it.
Life also required a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of hea
A. it is impossible for life to exist on planets
B. earthlike life could only exist on a few planets
C. life could exist on only one planet in a million
D. life could exist on a great number of planets

[单项选择]

Many scientists today are convinced that life exists elsewhere in the universe—life probably much like that on our own planet. They reason in the following way.
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere, a larger one would hold too much of it.
Life also required a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady
A. has different laws
B. has one common law
C. shares the same laws
D. shares no common law

[单项选择]Many scientists are so convinced of the benefits of challenging the brain that they are putting it into practice in their lives（）
A. 许多科学家都确信，在他们的生活中，经常练习挑战大脑，就会带来效益。
B. 许多科学家都对勤于动脑的益处确信不移，他们在自己的生活中也努力实践着。
C. 许多科学家都如此确信挑战大脑会带来利益，他们的实际生活证实了这一点。
D. 许多科学家都相信，他们生命中所实践的就是对人的大脑挑战，这种挑战是有益的。

[单项选择]A. Scientists are convinced that most animals cannot adapt to changes in climate.
B. Certain animals are more adaptable as they can live in extreme conditions.
C. Climate changes are responsible for the disappearance of some species.
D. Some species can move to the new surroundings in case of climate changes.

[简答题]

Today many people who live in large metropolitan areas such as Paris and New York leave the city m summer. They go to the mountains or to the seashores to escape the city noise and heat. Over 2.000 years ago, many rich Romans spent their summers in the city of Pompeii. Pompeii was a beautiful city. It was located on the ocean, on the Bay of Naples. In the year 79 A. D., a young Roman boy who later became a very famous Roman historian was visiting his uncle in Pompeii. The boy’s name was Pliny. One day Pliny was looking at the sky. He saw a frightening sight. It was a very large dark cloud, this black cloud rose high into the Sky. Rock and ash flew through the air. What Pliny saw was the eruption—the explosion—of the volcano. The city of Pompeii was at the foot of Mt. Vesuvius.
When the volcano first erupted, many people were able to flee the city and to escape death. In fact, 18,000 people escaped the terrible disaster. Unfortunately, there was not enoug