The book you want is not now. I will let you know as soon as it is returned to the library

问题补充：

The book you want is not now. I will let you know as soon as it is returned to the library.

A. useful

B. possible

C. available

D. practical

答案：

A. useful

B. possible

(答案→)C. available

D. practical

解析：试题分析：A有用的B可能的C可得到的，可利用的D实际的，实用的。根据句意：你要的书还拿不到，书一归还到图书馆我会立马通知你。