______ people have become masters of the

问题选择题

______ people have become masters of their country ____ science can really serve the people.

A．It is only then ;that

B．It is that;when

C．It is only when; that

D．It is when;when

答案

答案：C

此题是一个强调句型，强调的是时间状语从句，强调句的结构为it is/was + 被强调的部分 + that,句意：只有当人们已经了解了他们的国家的时候科学才真正的为人民服务，所以选C。