23.You have greatly __ us.What you have done is not what you

23.You have greatly __ us.What you have done is not what you told us about several weeks ago.
A.disappointed B.deserted C.clarified D.opposed
24.Before you begin writing your paper,please write__ first.Then we can have a better idea about what you are going to talk about.
A.an origin B.a detail C.an example D.an outline
25.If you ask why I plan to study in the United States,my answer is simply that it is a ________for me.
A.chapter B.ceremony C.chamber D.challenge