The Nile River ____ flood large areas but now the water ____ produce electricity.
| A．used to; is used to | B．used to; used to |
| C．was used to; is used to | D．was used to; used to |
_____ good, these cookies sell well.
| A．Smelled | B．Smelling | C．Being smelled | D．To smell |
What ______ public is concerned about is whether medical workers and scientists will be able to find for this new disease in a short time.
| A．不填;不填 | B．不填;the | C．the;不填 | D．the;a |
You can’t imagine that a well –behaved gentleman ______ be so rude to a lady.
| A．might | B．need | C．should | D．would |
My sister met him at the Grand Theatre yesterday afternoon, so he ________ your lecture.
| A．couldn’t have attended | B．needn’t have attended |
C．mustn’t have attended | D．shouldn’t have attended |
—How is that, Joan?—Yeah, it’s from the boss. She _________ first, whether she likes it.
| A．shall go | B．ought to have gone | C．should go | D．must have gone |