1) The shy boy did not have the courage to put his hat on with Mary ____him.

1) The shy boy did not have the courage to put his hat on with Mary ____him.
A.watching B.watched C.to watch D.watches
为什么是watching而不是watched?
2)I failed to pass the exam though my beloved teacher ______.
A.was expected me to B.expected of me C.is expected of me D.expected me to 答案为什么是D呢?
3)The tourist was unable to make himself___because of his poor English.
A.understood B.be understanding C.being understood D.be understood
这个为什么是A呢?
分析的越详细越好,但要简明扼要,