在精加工工序中,加工余量小而均匀时可选择加工表面本身作为定位基准的为()。
A、基准重合原则
B、互为基准原则
C、基准统一原则
D、自为基准原则
参考答案:D
The girl had hardly rung the bell _____ the door was opened suddenly, and her friend rushed
out to greet her. [ ]
A. before
B. until
C. as
D. since
采取简易程序的产品后评估工作应当在()个工作日内完成。
A.10
B.20
C.45
D.60