I believe you have done your best and things will improve .A. that.\B. \.\C. what thatD

问题补充：

I believe you have done your best and things will improve .

A. that.\

B. \.\

C. what, that

D. \.that

答案：

A. that.\

B. \.\

C. what, that

(答案→)D. \.that

解析：考查宾语从句的连接词。如果动词后面有两个或者两个以上的由that引导的宾语从句，第一个宾语从句的that可以省略，后面的都不能省略。本题第一空省略了that第二空中的that没有省略。句意：我认为你已经全力以赴了，情况也会变好了。故D正确。