The boss____________ the worker how to do it, or the accident couldn't have happened.
| A．can't have told | B．ought to tell |
| C．could have told | D．mustn't have told |
—Can I call you back at two o’clock this afternoon?
—I’m sorry, but by then I______ to Beijing. How about five?
| A．fly | B．will fly | C．will be flying | D．am flying |
I______ thank you too much for all your help to my son while we were away from home.
| A．won’t | B．can’t | C．can | D．will |
If he takes on this work, he will have no choice butan even greater challenge.
| A． | meets | B． | meeting | C． | meet | D． | to meet |
—The trip shouldn’t take more than an hour.
—_______.it is at least two hours.
| A．I guess so | B．That’s it |
| C．You must be joking | D．It depends |
As many as five courses are provided, and you are free to choose ______ suits you best.
| A．whatever | B．whichever | C．whenever | D．wherever |