单选题 A single rocket is not powerful enough to send a spaceship into space. This is because all the fuel a single rocket can. carry is not enough to give the necessary amount of power. To get enough fuel and power to last till the spaceship gets out of the Earth's gravitation force (引力) , a number of rockets are needed. These rockets are connected one on top of the other, looking much like a large tower. Together they form a multi-stage rocket. The spaceship lies at the top of the multi-stage rocket.
The first stage of a multi-stage rocket is called the booster. It is the biggest as it has to lift the whole thing from the ground. The booster helps to lift the rockets into the sky. When the fuel of the booster is used up, it separates from the rest of the rocket and drops to the Earth. When this happens, the second stage fires and pushes the rocket further towards space. After some time the second stage, having used up its fuel, just like the booster, separates and falls off. The spaceship is then left to travel to its destination on its own power.

单选题 ______ can send a spaceship into space.

【正确答案】 D

【答案解析】此题题干问“什么可以把太空船送到太空”。在原文第1段第3、第4和第5句话可以得出多级火箭帮助把太空船送到太空。因此选项D. The multi-stage rocket是正确答案。

单选题 A multi-stage rocket refers to ______ .

A、 several rockets which are separated from each other
B、 a single rocket with enough fuel
C、 the booster which is the biggest and can lift the whole rocket from the ground
D、 a rocket with several parts, and each of which can help to push the spaceship into the space

【正确答案】 D

【答案解析】本题题干问“多级火箭指的是什么”。原文第1段第3、第4和第5句话指出连接在一起的几个火箭，帮助把太空船送到太空。因此选项D. a rocket with several parts, and each of which can help to push the spaceship into the space是正确答案。

单选题 The booster falls off as soon as ______ .

【正确答案】 A

【答案解析】本题题干问“第一级火箭何时脱落”。原文第2段第4句话指出当第一级火箭所携带燃料用完后与二级火箭脱落。因此选项A. it uses up its fuel是正确答案。

单选题 After ______ falls, the spaceship travels in space itself.

【正确答案】 D

【答案解析】本题题干问“在第几级火箭脱落后，太空船进入太空飞行”。原文第2段第7和第8句话指出当第三级火箭脱落后，太空船靠自身动力飞往目的地。因此选项D. the third rocket是正确答案。

单选题 Which of the following is TRUE?

A、 The spaceship travels to its destination with its own fuel.
B、 The booster separates and drops when all the fuel it carries has used up.
C、 The multi-stage rocket is powerful enough to send the spaceship to its destination.
D、 The spaceship gets out of the Earth's gravitation force and flies to its destination on its own.

【正确答案】 B

【答案解析】本题测试辨认正确信息的能力。原文第2段第4句话指出当第一级火箭所携带的燃料用完后与二级火箭脱落。因此选项B. The booster separates and drops when all the fuel it carries has used up. 与原文意思一致，是正确答案。