It ________ be the postman at the door.It's only six o'clock.( 2011·江西)
| A．mustn't | B．can't | C．won't | D．needn't |
--- How long have you been here?
--- _____ the end of last month.
| A．In | B．By | C．At | D．Since |
We keep in touch ____ writing often.
| A．with | B．of | C．on | D．by |
Who is it up _____ decide whether to go or not?
| A．to to | B．for for | C．to for | D．for to |
____ that they are inexperienced, they have done a good job.
| A．Giving | B．To give | C．Given | D．If given |
Thank you for the trouble you have ____ to help me.
| A．paid | B．taken | C．had | D．asked |