现代数控系统大多是计算机数控系统
参考答案:对
--- Why didn’t Mr. Smith arrive on time for the meeting?
--- He must have been ________ on his way here in the traffic jam.
A.held up
B.put up
C.taken up
D.given up
希腊最主要的文明集中在()的两个半岛。
A、北方
B、东方
C、南方
D、西方