根据句意和首字母提示补全单词。

1. There is n________ much wrong with you, just have a rest.

2. Lei Feng always helped others in his l________. We should learn from him.

3. —Who can s________ the math problem?

    —I think everybody can.

4. China now p________ enough rice to feed her people every year.

5. In his s________ time, he loves playing the violin and listening to music.

6. Yuan Longping is now working on d________ super hybrid rice.

0.5时：45秒的最简整数比是______，比值是______．