一般轻型井点设备由（）组成。
A.管路系统
B.抽水设备
C.总管
D.井点管
E.滤管
参考答案：A, B
She asked me if I knew ______ . [ ]
A. whose pen is it
B. whose pen it was
C. whose pen it is
D. whose pen was it
二次移动平均法，适用于时间序列呈现（）变化的预测。
A.线性趋势
B.非线性趋势
C.二次曲线趋势
D.三次曲线趋势
