Don’t come into the lab ________ you are asked to.
| A．unless | B．until | C．because | D．since |
_________ the classmates’ help, we won the basketball final at last.
| A．To | B．With | C．For | D． Under |
He is very serious. No one can make him___.
| A．laugh | B．laughs | C．to laugh | D．laughing |
—I knocked into a tree when I went to the bus stop for my friend.
—I suppose you _____too fast.
| A．had driven | B．are driving | C．drove | D．were driving |
this key is your mother’s.
| A．May | B．Maybe | C．May be | D．Can |
You don’t know ______ I want to see you again. It’s a year since I last saw you.
| A．how soon | B．how long | C．how much | D．how often |