锤头有软硬之分,软锤头用于()和()。
参考答案:装配;校正
We should find a _____place for a picnic. I mean, it is not far away from here and it is very quiet.
A.beautiful
B.public
C.warm
D.proper
放空管一般应设在设备或容器的顶部。间歇排放的放空管口应高出()m范围内的平台或建筑物顶3.5m以上。
A.10
B.20
C.30
D.40