__________ some medals came to live in the sea is not known.
| A．Which | B．Since | C．Although | D．How |
He _______ speak to his mother like that.
A ought not to B. doesn’t ought to C not ought to D ought to not
--- Isn’t that Jessica’s brother over there?
--- No, it _______ be him. I’m sure he doesn’t wear glasses.
A. can’t B. must not C won’t D may not
She was fired by the boss because she failed to ___________ for work on Monday.
A. turn up B. turn down C. turn on D turn out
Great changes _________ in China in the last two decades.
| A．have taken place | B．took place |
| C．have been taken place | D．are taking place |
We must set a limit __________ the expense of the trip.
| A．to | B．on | C．for | D．with |