2) heavy duty

重负载的
3) heavy duty

重载的
5) block repetition definition

块的重定义
1.
This paper introduces the operation and skill of application of block in AutoCAD to simplify mechanical drawing,including the reasonable use of the property block,the block repetition definition and so on.
介绍了应用AutoCAD的块来简化机械绘图的操作方法和技巧,包括合理利用属性块、块的重定义等。
6) high duty

高负荷的,重载的,重负载