题目

下列有关显微镜使用的说法中，不正确的项是（ ） A . 对光时，应使用低倍物镜 B . 放大倍数越大，则视野越暗 C . 要想将视野调得明亮些，可使用平面反光镜或较小光圈 D . 若把视野右上方的物像移至视野中央，玻片标本应向右上方移动 答案：CScientists said they have found evidence of a giant planet far out in our solar system. In a statement, the California Institute of Technology(Caltech) said this planet travels a strange “highly elongated orbit in the distant solar system”.The discovery was made by two researchers at Caltech; Konstantin Batygin and Mike Brown. They used mathematical modeling and computer simulations (模拟)to find the planet. So far, there have not been any direct observations of the planet. “My jaw hit the floor,” said astronomer Mike Brown, the moment he realized there might be a ninth planet.The scientists said it would take this planet 10,000to 20,000 years just to make one full orbit around the sun. The new planet, called “Planet Nine” has a mass about 10 times the size of Earth.It is believed that the planet orbits, or travels, around the sun from a great distance. The planet Neptune’s average distance to the sun is about 4.5 billion kilometers. But “Planet Nine” could be 20 times farther away from the sun than that. While they did not get a picture of “Planet Nine” yet, the scientists say they are using the biggest and best telescopes on Earth to try to find it.Brown and Batygin reported their finding in The Astronomical Journal. They say that this new planet is so large that there should be no doubt that it is a true planet, once they confirm it.Robert Massey is with the Royal Astronomical Society in London. He told AFP that planets have been predicted before, and then were not found. But, he said the work of the these researchers is definitely worth following up. “It would be a really exciting thing to find. At the moment it’s simply a prediction.”1.How was the evidence of the ninth planet found?A. Through a special telescopeB. Through researchers’ direct observationC. Through studying its special orbit in the solar systemD. Through mathematical modeling and computer simulations2.What can we know about “Planet Nine” from the text?A. It is much smaller than the earthB. It travels a normal orbit like other planetsC. Its distance to the sun is about 90 billion kilometersD. Its picture has been caught by the biggest and best telescope3.What’s Robert’s attitude towards the discovery of “Planet Nine”?A. Worried B. SupportiveC. Indifferent D. Opposed4.What’s the best title for the text?A. The discovery of the largest planetB. A big prediction of the solar systemC. A ninth planet may be in the solar systemD. The ninth planet has been found in the solar system