句型转换。

1. I finally work out the problem. (改为同义句)

    I work out the problem _____ _____.

2. I want to buy a bag of rice. (对划线部分提问)

    _____ _____ rice _____ you want to buy?

3. There are many watermelons on the farm. (对划线部分提问)

    _____ _____ watermelons are there on the farm?

简述全麻的并发症？