题目

科考船对某海域的海底形状利用声呐系统进行了测绘。具体方法是：在经过该海域水平面等间距的A、B、C、D、E五个位置时，向海底定向发射超声波，测得回收信号的时间分别为0.30s、0.16s、0.30s、0.14s、0.30s。根据时间，求出海底与海平面的距离，就可以绘出海底的大致形状，则该海域海底的大致形状如图中的（ ） A . B . C . D .A Chinese rocket carrying a probe（探测器）destined（预定） for the moon has been sent into space. A Long March 3C rocket with the Chang’e -2 probe took off from Xichang launch centre at about 11: 00 GMT. The rocket will shoot the craft into the trans-lunar orbit（绕月轨道）,  after which the satellite is expected to reach the moon in about five days.  Chang’e -2 will be used to test key technologies and collect data for future landings.  China says it will send a rover（漫游者） on its next mission,  and it also has ambitions to put humans on the surface of the lunar body at some future date.  The Xinhua News Agency said Chang’e -2 would circle just 15 km (nine miles) above the rocky terrain（地带）in order to take photographs of possible landing locations. It is China’s second lunar probe—the first was launched in 2007. The craft stayed in space for 16 months before being intentionally crashed onto the moon’s surface. China launched its first manned flight into low-earth orbit in 2003; and two more followed, with the most recent one in 2008.  So far, only three countries have managed to independently send humans into space: China, Russia and the US. In 2008, a Chinese astronaut, fighter pilot Zhai Zhigang, performed a spacewalk—the first in China’s history. He stayed outside the Shenzhou-7 capsule for 15 minutes; the exercise was seen as the key to China’s ambition to build an orbiting station in the near future. 71. What’s Chang’e -2’s main task according to this passage? A. Landing on the moon just as the first lunar probe. B. Comparing with the first lunar probe. C. Competing with Russia’s and the US’s space crafts. D. Testing technologies and collecting data for future landings. 72. Which of the following about Chang’e -2 is TRUE? A. Its travel to the moon lasts about five days. B. It will put humans on the surface of the moon. C. It travels with Long March 3C rocket all the way. D. It will take photographs of the moon on the trans-lunar orbit. 73. China’s first lunar probe_______ . A. was launched in 2008 B. landed on the moon safely at last C. took Chinese astronaut Zhai Zhigang to the moon in 2007 D. accomplished its task in less than one and a half years in space 74. Which of the following is the best title for the passage? A. China Launches Moon Mission B. Chang’e -2 Is More Advanced than Shenzhou-7 C. China’s Space Program Makes Great Progress D. China Equals Russia and the US in Space Technologies 75. The underlined word“craft” in the third paragraph refers to_______. A. Chang’e -1 probe B. Chang’e -2 probe C. a rover D. the Shenzhou-7 capsule