水泵和管路系统能量供需关系失去平衡后，（）也相应发生变动。
A、局部水头损失
B、沿程水头损失
C、水泵装置工作点
D、全部水头损失
参考答案：C
In the office I never seem to have time until after 5:30 p. m., _____ many people have got home.
A whose time B. by that time
C. on which D. by which time
影响从众的个人方面的因素包括（）
A.性别
B.年龄
C.地位
D.个性特征
