Question

Criticism and self-criticism _____ necessary _____ it helps us to correct mistakes.

A．is, in that

B．are, in that

C．is, in which

D．are, at that

Answer 1

A

解析第一空是主谓一致，Criticism and self-criticism看成整体，谓语动词应用单数，第二空考查连词，in that  因为，句意：批评与自我批评是必要的因为它帮助我们纠正错误。所以选A。