7、关于下列结构说法正确的是( ) A.五种结构广泛地存在于各种细胞内 B.①③④⑤上进行的反应都需要②提供能量 C.①与③间的相互转化能体现生物膜的流动性 D.观察活细胞中的④常用健那绿染色 答案:C 9. His efforts to raise money for his program were because no one showed any intention to take a cent out of their pockets. A. in place B. in sight C. in effect D. in vain