单项选择题
You are required to write（）
A.an abstract B.an arrative passage C.an argumentative passage D.an expository passage
单项选择题 Please prepare the medicine for me according to this（）
单项选择题 Professor Smith promised to look（）my paper, that is, to read it carefully before the defence.
单项选择题 It's our duty to preserve the planet for future（）
