单作用式叶片泵转子每转一周，每个密封容积完成（）次吸油和压油。
A.4
B.3
C.2
D.1
参考答案：D
— How about putting some pictures into the report?
— A picture is worth a thousand words. [ ]
A. No way.
B. Why not?
C. All right?
D. No matter.
下列大小关系正确的是[ ]
A.-5>-3
B.|-5|>|-3|
C.-（-3）>-（-5）
D.|-3|>|-5|
