出版单位使用他人作品支付报酬的原则是（）。
A.平等原则
B.公平原则
C.公开原则
D.协商一致原则
E.等价原则
参考答案：A, B, D, E
已知an=3，bn=7，则（ab）n=______．
This is the first time that I _____ such an interesting film. [ ]
A. saw
B. see
C. have seen
D. had seen
