We arrive ________ school at 8:30.[ ]
A. in
B. for
C. at
D. on
答案：C
The higher the birds flew, _______ we could see them.
A．less clearly
B．the less clearly
C．more clear
D．more clearly
慢性心力衰竭时推荐使用的β受体阻断剂是（）
A.所有已上市的β受体阻断剂
B.美托洛尔
C.阿替洛尔
D.普萘洛尔
E.吲哚洛尔
