题目

如图，矩形ABCD中，AB=4，BC=2，把矩形ABCD沿过点A的直线AE折叠点D落在矩形ABCD内部的点D处，则CD′的最小值是（） A . 2 B . C . 2 -2 D . 2 +2 答案：CAs a child , Jack studied in a village school , _____ is named after his grandfather. A. which   B. where    C. what    D. that