题目

Wind power is an ancient source of energy ________ we may return in the near future.     A. in which         B. to which         C. on that      D. from which 答案：B 解析: 略在梯形面积公式S=12(a+b)h 中，a、b为常数，则S是h的（　　）A．反比例函数B．正比例函数C．不是函数关系D．不能确定