问题
选择题
_______the people have become masters of their country _______ science can really serve the people.
A．It is only then; that
B．It was that; when
C．It is only when; that
D．It was when; then
答案
答案：C
It is ... that ...是强调句式，强调的是when引导的时间状语从句。句意：只有当人民成为自己国家的主人时，科学才能真正为人民服务