The problem had become _____ in his mind, and he could not decide what to do about it.
| A．simplified | B．exaggerated | C．matured | D．isolated |
Jim won the award, _______ excited everybody in the class.
| A．which | B．that | C．this | D．it |
The reason ______ he gave for being late was ______ he overslept this morning.
| A．why; that | B．which; that | C．why; because | D．which; because |
In class the teacher’s humorous words often make every student ____ laughter.
| A．burst into | B．break into | C．fall into | D．come into |
Look out! Don’t get too close to the house ______ roof is under repair.
| A．where | B．that | C．whose | D．which |
The teacher said that Columbus _______America in 1492.
| A．discovered | B．found | C．had discovered | D．had found |