带有位置检测装置的进给系统一定是半闭环进给伺服系统。
参考答案:错
The English play _____ my classmates acted at the new year's party was really a great success. [ ]
A. for which
B. at which
C. in which
D. on which
原位癌是指()
A.原发部位的癌
B.癌细胞仅在上皮层内,没突破基底的癌
C.没有发生转移的癌
D.早期癌