__________at the door before you enter the office，or you’ll be considered impolite
| A．Knocking | B．Knocked | C．Knock | D．To knock |
You'd better ________ some money for special use.
| A．pick up | B．set aside |
| C．put off | D．give away |
To ________ it simply, if you don't apologize to him，you will lose this friend.
| A．put | B．make | C．speak | D．talk |
My suggestion is that you ________ much meat.
| A．wouldn't take | B．shall not take |
| C．not have | D．won't have |
When he was there, he ________ go to that coffee shop at the corner after work every day.
| A．must | B．should |
| C．would | D．might |
—Do you still remember when we went to Nanjing?
—I can't remember now but ________ sometime last summer?
| A．might it be | B．could it be |
| C．could it have been | D．should it have been |