单项选择题
A. though doing B. though done C. if done D. if doing
Having been praised by the teacher, the little girl ran...
单项选择题Having been praised by the teacher, the little girl ran back home, （）.
A. happily and satisfied B. eager and excitedly C. happy and satisfied D. anxiously and excitedly
By the end of last week. 611 people from 49 countries （...
单项选择题By the end of last week. 611 people from 49 countries （） to attend the meeting, with nearly half coming from the United States, Germany and Britain.
A. had registered B. have registered C. registered D. were registered
The doctor tried to do an experiment to find out the （）...
单项选择题The doctor tried to do an experiment to find out the （） of the medicine on the mice.
A. cause B. result C. reason D. effect
