My wallet is nowhere to be found. I______it when I was on the bus.
A．must drop
B．had dropped
C．must have dropped
D．should have dropped

未分类题______, our next step is to determine how to carry it out.A．The plan having been madeB．Making the planC．The plan being madeD．Having made the plan

未分类题Its reported diat by the end of this month the output of cement in the factory______by about 10%.A．will have risenB．has risenC．will be risingD．has been rising

未分类题What does the phase 'look over their shoulders' ( Lines 1~2,Para.2) mean?A．Have an eye on what students are talking about online.B．Pretend not to see anything when students need help.C．Limit their rights of talking freely online.D．Have routine checks at school.

未分类题Whats the main idea of this passage?A．Police are making use of the Internet to maintain good public order.B．Students should learn to protect their privacy online.C．Social networking websites have bad influence on high school students.D．Parents should take control of what their children are doing online.

未分类题For what was the Rockefeller Drug Laws criticized?A．They would be costly and ineffective according to past experience.B．It was the first time that drug laws had been passed in the U.S.C．They deprived the judges of their right to sentence with their own will.D．It would be better to send drug users for treatment instead to jail.