Of the two brothers, Bill is ______ younger one, and he is a quiet boy, ______ that most adults like very much.
| A．a; one | B．a ; the one | C．the; one | D．the ; the one |
If _____ carefully, the experiment will be successful.
| A．do | B．does | C．done | D．doing |
He is a man of few words, and seldom speaks until _____ to.
| A．spoken | B．speaking | C．speak | D．be spoken |
There are five pairs, but I'm at a loss which _____ to buy.
| A．to be chosen | B．to choose from | C．to choose | D．for choosing |
He was not an actor, who often appeared on stage, _____ a writer, writing stories.
| A．but | B．and | C．then | D．so |
I don't know whether to stay in teaching or _____ another job.
| A．trying getting | B．to try to get | C．trying to get | D．try get |