选用阀门时，应考虑由于各种不同的工况出现的阀门的承压情况，其可能承受的最大压力决定于（）。
A.公称压力；
B.试验压力；
C.工作压力。
参考答案：A
James, I'm too tired. Let's stop. a rest.[ ]
A having
B. have
C. to having
D. to have
There are over two thousand students in this school. (同义替换) [ ]
A. about
B. more than
C. less than
D. almost
