_______ 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
The research is so designed that, once _______, nothing can be done to change it.
A. begins B. having begun C. begun D. Beginning
