在坐标镗床上可以进行精确的长度测量,但无法进行精确的平面角度的测量。
参考答案:错
The beef_________now is for the dinner party.
A. being cooked B, cooked C .been cooked D. cooking
Sue ____ our children last Sunday when we were out. [ ]
A. babysit
B. babysitted
C. babysat