GRE数学考生常出错的题详解
1，l1, l2 and l3 are three lines in space The number of points at The number of points at which lines l1 and l2 intersect which lines l2 and l3 intersect 1.三条任意直线，L1和L2的交点的个数与L2和L3的交点的个数没关。 2. The number of 1/4-inch lengths in 1 a 4-inch length ...