问题
选择题
关于物体的惯性，下列说法正确的是（ ）
A．运动的物体有惯性，静止的物体没有惯性
B．物体不受力时有惯性，受力时没有惯性
C．物体在运动状态改变时有惯性，运动状态不变时没有惯性
D．物体在任何情况下都有惯性
答案
惯性是物体本身具有的一种性质．与物体是否运动、是否受力等外界因素无关．物体在任何状态下、任何时候都有惯性．
故选D．
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关于物体的惯性，下列说法正确的是（ ）
A．运动的物体有惯性，静止的物体没有惯性
B．物体不受力时有惯性，受力时没有惯性
C．物体在运动状态改变时有惯性，运动状态不变时没有惯性
D．物体在任何情况下都有惯性
惯性是物体本身具有的一种性质．与物体是否运动、是否受力等外界因素无关．物体在任何状态下、任何时候都有惯性．
故选D．
Task-based reading 任务型阅读 请认真阅读下面短文，并根据所读内容在文章后图表中的空格里填入最恰当的单词。注意：每空不超过1个单词。 For centuries people dreamed of going into space. This dream began to seem possible when high-flying rockets were built in the early 1900s. In 1903 a Russian teacher named Konstantin Tsiolkovsky figured out how to use rockets for space travel. His plan was the first one in rocket science to use correct scientific calculation. About 30 years later, a U.S. scientist named Robert Goddard built the first rockets that could reach high altitudes. During World War II, German scientists built large rockets that could travel very far and carry dangerous explosives. After the war, scientists from Germany went to the United States and the Soviet Union to help those countries build space rockets. These two countries were soon racing to get to space first. Each of these countries wanted to prove that it was stronger and more advanced than the other one. Both countries also had powerful bombs. People in the United States were worried when the Soviets were first to launch a space satellite, which was called Sputnik. The Soviets were also first to send a person into space. Yury Gagarin orbited the earth in the Vostok I spaceship in 1961. The US government set a goal for its space program to be the first country to put a person on the Moon. The U.S. space program built a series of Apollo spaceship. These vehicles were powered by huge Saturn 5 rockets. In 1969 Apollo II took three men to the moon successfully. Nell Armstrong became the first person to walk on the Moon. The Soviets may have lost the race to fly people to the Moon, but they built the first space station in 1971. The United States also built a space station. The space stations allowed people to live and work in space. Then the Soviet Union and the United States cooperated to hook two spaceships together in space. This action ended the "space race". Today a much larger space station, built by several countries together, orbits Earth. Another new way to go to space is by space shuttle. A space shuttle, first made in the United States in 1981, looks like an airplane. Astronauts who fly spaceships have used shuttles to help put satellites into space.
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