抹带有线角的方柱有两种工艺方法，即______和______。
参考答案：传统工艺；活模工艺
I didn't come to school yesterday I had to look after my grandmother at home. [ ]
A. because
B. because of
C. since
下列各项中，属于赋予特性的是( )。
A．快递员的送货时间 B．机器的生产率C．螺栓的直径 D．售后服务要求
