单项选择题
液氯与反应器间设置（）和缓冲罐。
A、截止阀B、止回阀C、蝶阀D、球阀
单项选择题 At first（）I thought it was Mary，but when I looked again I saw it was Jane.
单项选择题 They were evidently trying to（）the public into obedience.
单项选择题 He turned his pockets（）out in search of his tickets.
