—You didn’t wait for Mr. Black last night, did you?
—No, but we ____. He didn’t return home at all.
| A．couldn’t have | B．needn’t have |
| C．didn’t need to | D．should wait have |
You are______your time trying to persuade him;he’ll never join us.
| A．spending | B．wasting | C．losing | D．missing |
—You didn’t invite John to the party?
—______him,too?
| A．Should I invite | B．Should I have invited |
| C．Must I invite | D．Must I have invited |
She told me that her father______to the post office when I arrived.
| A．just went | B．has just gone |
| C．had just gone | D．had just been going |
By the time he was ten,Edison______experiments in chemistry.
| A．had already done | B．already had done |
| C．was already doing | D．already did |
______,the boy couldn’t enter his house.
| A．Since the key had lost | B．T he key being lost |
| C．Lost the key | D．Having lost the key |