A.Caffeine may help people think clearly.B.Caffeine helps keep people more awake.C.Caffein

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A.Caffeine may help people think clearly.

B.Caffeine helps keep people more awake.

C.Caffeine gives a jumpstart to the nervous system.

D.Caffeine may improve memory consolidation.

请帮忙给出正确答案和分析,谢谢!

热搜:a是b的充分条件,b是a的必要条件吗