问题
选择题
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
答案
答案：A
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。