工具式沟通的动机往往是（）
A.归属动机
B.实用动机
C.探索动机
D.以上都可以
参考答案：B
He is student at Oxford University, _____ for a degree in computer seience. [ ]
A. studied
B. studying
C. to have studied
D. to be studying
基坑的排水方法，可分为明排水和人工降低地下水位两种方法。
