52单词网 > 高中英语 > 高中英语题库 > The doctor will not carry out the operation it is necessary. [ ] A. as B. if C.

The doctor will not carry out the operation it is necessary. [ ] A. as B. if C.

来源:网络 时间:
The doctor will not carry out the operation it is necessary. [ ] A. as B. if C.

The doctor will not carry out the operation _______ it is necessary. 

[    ]

A. as   B. if

C. for  D. unless

试题答案

答案:D