1.leopard seal is the only pinniped_______preys on penguins and other seals.

A. that normally

B.that it normally. (答案是Ａ）

２．Ronald Reagon had served two terms as governor of California before______president.

A. he became

B.became. (答案是Ａ）

问，１的答案为何不是Ｂ，ＴＨＡＴ引导从句啊，所以从句应有个主语啊，Ａ不是少主语么？再者，如果１答案是Ａ，那２答案不该是Ｂ么？２题中为什么又用主语了？１题为什么不用？？谢谢！

A. that normally

B.that it normally.

这里leopard seal是主语，is 是谓语，the only pinniped是宾语。所以后面一定是修饰宾语的定语从句。后面的成分都是修饰宾语。你觉得呢？

２．Ronald Reagon had served two terms as governor of California before______president.

A. he became

B.became.

这里应该是before引导的壮语从句。后面应该是完整句。你觉得呢？