选择车辆类型时，要将（）原则作为选型的标准。
A.经济性
B.通用性
C.轻巧性
D.美观性
E.适用性
参考答案：A, E
两条平行直线l1：x+2y﹣3=0，l2：x+2y+7=0之间的距离是（ ）
We found Mary's brother had ________ more story books than Ann's. [ ]
A. very
B. too many
C. by far
D. far
