______ is very good exercise for the mothers-to-be.
(A) Swimming (B) To swim (C) Go swimming (D) Swim
答案是A,想知道B为什么不行,不是toV也可以当主词
A strong man with a gun was seen ______ Mr. Wang’s house. That man must
have been a
robber.
(A) to enter (B) enter (C) entering (D) to entering
答案是A想知道C可以选吗
因为手边上面资料写S+be+seen/heard+to V /Ving,那其他的感官动词是否也有这个用法
Tolkien’s famous series of novels, The Lord of the Rings, ______ by people
all over the
world.
(A) read (B) reading (C) is being read (D) has been read
答案是D
想知道A为什不能选,空格变成 which are read简化后剩read这样可以吗?
还有确认关代和beV省略的确切用法
谢谢