零担货物中转作业的基本方法有（）。
A、坐车
B、加装
C、过车
D、换装
E、落地
参考答案：A, C, E
Your shoes ______ easily but they ______ well. [ ]
A. wear; haven't worn
B. are worn; haven't worn
C. wear; haven't been worn
D. are worn; haven't been worn
四肢静脉的内表面，通常具有防止血液倒流的静脉瓣。[ ]
