is certain the Normans conquered England in 1066 and then English changed.
A. That; that
B. It; what
C. That; what
D. It; that
网友回答
A. That; that
B. It; what
C. That; what
(答案→)D. It; that
解析：这是一道考查主语从句的题。It是形式主语，后面用that引导真正的主语从句。句意是“可以肯定的是，在1066年诺曼人征服英国，然后英语发生了改变。”