We can infer from the passage that fighting a problem is ______.
A. always sensible
B. sometimes useless
C. annoying
D. rewarding
查看答案
How did Dr. Edward Jenner solve the problem of smallpox？
A. He kept on focusing on people who had smallpox.
B. He changed his way of thinking by turning to people without smallpox.
C. Dairymaids advised that he use cowpox to experiment.
D. He happened to discover cowpox and he experimented with it on dairymaids.
A. Therefore B. Similarly C. Otherwise D. But
A. Therefore
B. Similarly
C. Otherwise
D. But
A. free B. for C. aboutD. with
A. free
B. for
C. about
D. with
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