When he the door, he found his keys were nowhere.
| A．would open | B．opened | C．had opened | D．was to open |
The manager came over and asked the customer how ___________.
| A．did the quarrel come about | B．does the quarrel come about |
| C．the quarrel has come about | D．the quarrel had come about |
－Are you sure you have to? It’s been very late.
－I don’t know ________ I can do it if not now.
| A．how | B．what | C．when | D．that |
Is it the letter you got yesterday ________ makes you so sad?
| A．what | B．that | C．how | D．when |
It’s important to listen to your teacher carefully in class, so try not to let your mind _________.
| A．lose | B．stop | C．wander | D．disturb |
－Do you mind if I turn off the TV?－__________.
| A．Yes, please | B．No, go ahead | C．Yes, you can | D．No, I’d rather you didn’t |