画分解式轴侧装配时，应先画出装配体中（）的轴测图。
A、单个零件
B、主体零件
C、装配方向
D、坐标轴
参考答案：B
—How clean and tidy your room is!
—Thank you. It____ every day. [ ]
A. is cleaned
B. was cleaned
C. was cleaning
D. is cleaning
人类的祖先是（ ）
A．猴子
B．类人猿
C．森林古猿
D．灵长目动物
ned