John opened the door. There _____ he had never seen before.
| A．a girl did stand | B．a girl stood |
| C．did a girl stand | D．stood a girl |
I know that it will be difficult to pick him out in such a crowd, but if you ________ happen to see him, give him this packet.
| A．would | B．might |
| C．should | D．could |
She didn't come to the party last Sunday. ________， she must have made the party more exciting.
| A．If she came | B．Would she come |
| C．Had she come | D．Did she come |
Students ________ remain in their seats until all the papers have been collected.
| A．would | B．shall |
| C．will | D．could |
—Did Ann fail in English?
—She ________. Don't you notice that she looks depressed?
| A．might | B．must |
| C．may have | D．could have |
I wrote a letter to John for his help during my high school years，without which I ________ the college entrance exam.
| A．would fail | B．would have failed |
| C．should fail | D．must have failed |