第27题: [单项选择]反相高效液相色谱是指() A. 固定相和流动相都是极性的 B. 固定相和流动相都是非极性的 C. 固定相是极性的,流动相是非极性的 D. 固定相是非极性的,流动相是极性的 E. 固定相和流动性极性相差大的 参考答案:D 答案解析:反相高效液相色谱是指固定相是非极性的,流动相是极性的。
第29题: [单项选择]Questions 30 to 32 are based on the passage you have just heard. A. Philip was a rude boy. B. Philip was asked to leave the library. C. Philip was not old enough to read in this library. D. Philip damaged the hook by falling it to the floor. 参考答案:C 答案解析:[听力原文] What can we learn from the passage