英语难题求助~请从语法角度加以说明~非常感谢!（2）

题目

英语难题求助~请从语法角度加以说明~非常感谢!（2）
31.the world has never had a bigger_________ concert than this one.
A. alive B. lively C. live D. living
33.the doctors have done everything they can_______ the man’s life.
A. save B. saving C. to save D. for saving
36.it_______ ten years since we last_______ in Beijing.
A. was…met B. had been…met C. was…meet D. is…meet
33题中为何can后面要跟不定式呢。。。为何不跟动词原型？

答案

31.the world has never had a bigger_________ concert than this one.
A.alive B.lively C.live D.living
C."现场"的意思
A.是"活着的"的意思
B.是"活着的"的副词
D.是"正在活着..."
3.the doctors have done everything they can_______ the man’s life.
A.save B.saving C.to save D.for saving
C.do sth to sth 试图做某事来完成某事
36.it_______ ten years since we last_______ in Beijing.
A.was…met B.had been…met C.was…meet D.is…meet
B."since"是用完成时的标志.所以用B
自从上次我们再北京见面后,我们都有十年没有碰到了.