( )个十和( )个一组成数字89。
8;9
— So, you didn't take his advice?
— No. _____ his advice, I _____ such a silly mistake. [ ]
A. Were I to take; shouldn't have made
B. If I had taken; would make
C. Had I taken; wouldn't have made
D. Have I taken; won't have made
在机械图样中,细点画线一般用于表示轴线、()、轨迹线和节圆及节线。
A、对称中心线
B、可见轮廓线
C、断裂边界线
D、可见过渡线