33. ______ happened to be no one in that house when the typhoon hit the area.
| A．It | B．There | C．This | D．That |
_______ that he made an obvious mistake, Jeff went on with his speech.
| A．Not realized | B．Not to realize |
| C．Not to have realized | D．Not realizing |
ack went to college last year, _______ to return home until he achieves his goal.
| A．determined not | B．determining not |
| C．not determined | D．not determining |
_______ in the queue for half an hour, Tom suddenly realized that he had left his wallet at home.
| A．To wait | B．Having waited | C．Have waited | D．To have waited |
_______ to sunlight for too much time will do harm to one’s skin.
| A．Being exposed | B．Exposed |
| C．Having exposed | D．After being exposed |
The bell _______ the end of the period rang, _______ our heated discussion.
| A．indicated; interrupting | B．indicating; interrupting |
| C．indicating; interrupted | D．indicated; interrupted |