________ at the door before you enter my room, please.
| A．Knock | B．Knocking | C．Knocked | D．To knock |
I'll go to the library as soon as I finish what I ________.
| A．was doing | B．am doing |
| C．have done | D．had been doing |
“The moment ________ soon”，he thought to himself，waiting nervously.(2012·湖南)
| A．came | B．has come |
| C．was coming | D．is coming |
—I'm not finished with my dinner yet.
—But our friends ________ for us.(2010·北京)
| A．will wait | B．wait |
| C．have waited | D．are waiting |
It's really time I went home but I'm enjoying myself, so I ________ here a bit longer.
| A．am staying | B．have stayed |
| C．stayed | D．stay |
The sky is clouding over；we can see there ________ a rainstorm.
| A．is going to be | B．is going to have |
| C．will be | D．will have |