挡土墙是设置于天然地面或人工坡面上，用以抵抗（）土压力，防止墙后土体坍塌的支挡结构物。
A.垂直向上
B.垂直向下
C.任意
D.侧向
参考答案：D
--Where is Mary? I’d like to have a talk with her.
--She _______________the library. You can find her there.
A．has been to
B．has gone to
C．has left
D．will leave
下列程序段的执行结果为______。 Dim m(3,3)As Integer Dim i As Integer Dim j As Integer Dim x As Integer For i=1 To 3 m(i,i)=i Next For i=0 T0 3 For j=0 To 3 x=x+m(i, j) Next Next Print x
A．3
B．4
C．5
D．6
