Ⅰ.根据句意及首字母或汉语提示完成句子
1．Mars is a p________ and it moves around the sun.
2．The old man often listens to the n________ on the radio.
3．I heard that you were making a m________ plane.
4．Zhai Zhigang is a famous ________(宇航员) of our country.
5．I hope to travel to space by ________(宇宙飞船)．
