the end of the match, we had kicked four goals. [ ]
A. At
B. By
C. In
D. On
答案:B
断肢(指)再植术后突然发生的循环危象,大多数由于()形成所致。渐渐发生的供血不足,一般由于()所引起。
设有下列二叉树:
对此二叉树先序遍历的结果是