第19题: [多项选择]关于细菌的带电现象正确的是() A. 革兰阳性菌等电点为pH2~3 B. 革兰阴性菌等电点为pH4~5 C. 革兰阳性菌等电点为pU4~5 D. 革兰阴性菌等电点为pH2~3 E. 在中性或弱碱性环境中,细菌均带负电荷 参考答案:A, B, E
第20题: [单项选择]Which of the following is a sentence with a metaphor A. He is a wise fool. B. If Winter comes, can Spring be far behind C. Boys and girls were moving jewels while playing in the street. D. He is as dead as a nail. 参考答案:C