— Show me your permit, please.
—Oh, it's not in my pocket. It
| A．might fall out | B．could fall out |
| C．should have fallen out | D．must have fallen out |
There, in the corner, sat three girls,_______.
| A．sew | B．were sewing | C．to sew | D．sewing |
_______the early train,you'll have to get up early and rush in a taxi.
| A．Catching | B．Caught | C．To catch | D．Catch |
The_______waiter came up to us and said,"You are welcome."
| A．smiling | B．smiled | C．smile | D．to smile |
There is a big dog_______to a fence outside the house.
| A．tying | B．tied | C．to tie | D．ties |
Tell Mary that there's someone_______for her at the door.
| A．waiting | B．waited | C．waits | D．to wait |