_____ to school this morning, I met a friend of mine.
| A．I was walking | B．Walking |
| C．While I walking | D．Walked |
It was playing computer games that cost the boy a lot of time that he __________ doing his lessons.
| A．might have spent | B．ought to have spent |
C．must have spent | D．could have spent |
Professor Smith, many students want to see you. __________ they wait here or outside?
| A．Do | B．Shall | C．Will | D．Would |
Better go to see my sick colleague right now, ________I?
| A．hadn’t | B．didn’t | C．don’t | D．won’t |
I promised to get there before 5 o’clock, but now the rain is pouring down. They ______ for me impatiently.
| A．may wait | B．ought to wait | C．could wait | D．must be waiting |
She’s already an hour late, What _____to her?A can have happened B may happenC should have happened D may have happened