What ____________ Ben and his family usually do?[ ]
A. is
B. have
C. do
答案:C
数控机床编程序时常用刀具补偿,下面()是错误的。
A.刀具左补偿
B.刀具右补偿
C.刀具长度补偿
D.刀具直径补偿
养老机构根据不同服务对象采取不同的服务标准,一般分为()和特护护理服务两种。