It is high time that you（）smoking.

单项选择题（）I can't help admiring the man's courage, I do not approve of his methods.

A. Unless
B. While
C. Since
D. Although

单项选择题He is one of the leaders（）to attend the important international conference.

A. who have been invited
B. who has been invited
C. whom they have invited him
D. whom has been invited