龙骨安装时,弹线应清楚,位置准确,其水平允许偏差()㎜。
A.±4
B.±5
C.±4.5
D.±6
参考答案:B
I've had a cookie,but you'd better give me________.I want to taste again.
A.other
B.another
C.others
D.the other
方向控制阀分为单向阀和()。
A.溢流阀
B.换向阀
C.顺序阀
D.减压阀