4.美国“发现”号航天飞机会带肯尼迪航天中心之前。佛罗里达恶劣的天气，加上舱门的故障，曾使安全着陆难以保证。
Before the American space shuttle Discover returned to Kennedy Space Center, the bad weather in Florida,coupled with the door trouble, put its landing in doubt.
5.迄今为止还没有充分证据表明火星上有生命，但这并不是说外层空间的研究没有科学价值。
So far there is little evidence of life on Mars ,but this doesn’t justify the conclusion that research has no scientific value.
6.国际空间站是费用最为昂贵的太空探索项目，是有十六个国家参与的合作项目。 The International Space Station, a collaboration in which sixteen countries are taking part , is the most expensive space-explooration project ever undertaken.
7.这本书讲的是在五十年代末，中国航天探索的先驱者在没有外国专家帮助的情况下，执着的进行研究的情况。
This book describes the period at the end of 1950s when the pioneers of Chinese space exploration pressed ahead with their research without the help of foreign experts.
8.今年制造业创利已超过两千亿美元，占我国国内生产总值的一半。
This year the profits made in manufacturing industries have exceeded $200 billion,
making up one half of our country’s GDP.