14.WhileA he thinks the phenomenonB is the result of enzyme action, I believe it is caused byC a shortage ofD a neurotransmitter. No errorE.! E' f) m' l3 U2 V) o' g3 ?
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答案是A,,我郁闷了,WHILE可以当虽然讲,但答案是这样说的 While should be used for simultaneous actions. Change to though.