箱体零件图中长、宽、高三个方向常选用()作为尺寸基准。
A.轴孔中心线
B.底面
C.顶面
D.对称平面
E.结合面
F.安装基面
参考答案:A, D, E, F
---Why didn’t Sally play the violin at the concert last night?
---She said that her hand hurt, but that was only a(n) _______. I saw her play tennis just now.
A.matter
B.excuse
C.result
D.expression
[说明] 下面的流程图实现了正整数序列{K(1),K(2),…,K(n)}的重排,得到的新序列中,比K(1)小的数都在K(1)的左侧,比K(1)大的数都在K(1)的右侧。以n=6为例,序列{12,2,9,13,21,8}的重排过程为:{12,2,9,13,21,8} →{2,12,9,13,21,8} →{9,2,12,13,21,8} →{8,9,2,12,13,21}[流程图]