Alice fixed her eyes upon Bob, there was an expression __ that he could not understand.
| A．in it | B．on them | C．in them | D．on it |
We'd better hurry ______ it is getting dark.
| A．and | B．but | C．as | D．unless |
I didn' t manage to do it _____ you had explained how.
| A．until | B．unless | C．when | D．before |
_____ he comes, we won't be able to go.
| A．Without | B．Unless | C．Except | D．Even |
I hurried _____ I wouldn't be late for class.
| A．since | B．so that | C．as if | D．unless |
_____ I catch a cold, I have pain in my back.
| A．Every time | B．Though | C．Even | D．Where |