— Hello, Tim! What's that?
— It's _____ eraser. [ ]
A. a
B. an
C. the
D. 不填
答案:B
—I wish you’ll have a great time. —______.
A.I don’t think so
B.No
C.Thanks a lot
D.Yes
防洪(防浪)墙的断面形式不包括()。
A.重力式
B.扶壁式
C.悬臂式
D.缓坡式