第20题: [单项选择]A well coherent discourse ______ good choice of cohesive devices and semantic selection among other things. A. calls for B. calls on C. calls up D. calls forth 参考答案:A 答案解析:短语动词辨析题。选项[A]call for意为“要求,需要”;选项[B]call on意为“命令,要求”;选项 [C]call up意为“使人想起”;选项[D]call forth意为“唤起,振奋”。