18. It was because of English girlfriend, believe it or not, ______ his English improved so greatly.
| A．which | B．as | C．that | D．what |
Boris has brains. In fact，I doubt whether anyone in the class has ____IQ.
| A．a high | B．a higher | C．the higher | D．the highest |
Yesterday Jane walked away from the discussion. Otherwise，she ____ something she would regret later.
| A．had said | B．said | C．might say | D．might have said |
An awful accident_____，however，occur the other day.
| A．does | B．did | C．has to | D．had to |
Greenland， _____ island in the world，covers over two million square kilometers.
| A．it is the largest | B．that is the largest | C．is the largest | D．the largest |
_____， he often forgot to turn off the lights.
| A．Even better | B．Strange | C．However | D．Fortunately |