Susan often goes to school _____________ 7 o'clock. [ ]
A. on
B. in
C. at
D. for
答案:C
( )即以低于合理水平的证券交易佣金标准争抢客户的不正当竞争行为。
A.佣金价格战 B.市场价格战 C.证券营销战 D.不正当竞争