Countries around the 【小题1】 are spending billions of dollars and lots of time on 【小题2】 space missions, 【小题3】 to Mars or other planets much further away. Some people argue that we should stop wasting time and money exploring space. 【小题4】, we should feed the world’s poor and find 【小题5】 solutions to other problems, such as pollution and fatal diseases. However, others feel this is a shallow view which fails to realise how exploring space helps us.

Day after day, year after year, Earth 【小题6】 around the sun. The sun is the centre of our solar 【小题7】 and, in a way, it is our anchor. 【小题8】 the strong pull of its gravity, the sun keeps the Earth 【小题9】 orbit. The sun also is our major source of energy. Without the sun’s light and heat, life on Earth 【小题10】 not exist.