But now _____ the difficult bit.
A. did come
B. came
C. come
D. coming
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He played basketball in the afternoon _____ doing his homework.
A. and
B. but not
C. except
D. instead of
He walked out of the cinema _____ the stadium.
A. to
B. opposite
C. past
D. along
体内有多种高能磷酸化合物,参与各种供能反应最多的是:
A. 磷酸肌酸
B. ATP
C. UTP
D. PEP
氰化物是剧毒物,使人中毒致死原因是:
A.使血红蛋白不能贮存O2
B.破坏cytb和c之间的电子传递
C.破坏cytc1和c之间的电子传递
D.抑制细胞色素氧化酶