They started the job six months ago. They______it by now.
A. would have finish
B. can have finished
C. should have finished
D. must have finished
从文中可以看出,作者对给长辈红包这种现象的态度是:
A. 反对
B. 支持
C. 观望
D. 无所谓
不定期地进行察访并给予奖酬属于_______的强化手段。
A. 固定间隔安排
B. 自然消退
C. 可变间隔安排
D. 负强化
他家的楼下是:
A. 监狱
B. 酒馆
C. 妓院
D. 法庭