【单选题】What does the man mean?
B.
He does not know what to do.
C.
He does not know what to say.
【单选题】________ you know Peter?
【简答题】A.He does not know who Alice is. B.He has found a job as a messenger. C.He does not want to deliver the note. D.He does not know who Alice is.
【单选题】A man does not know the difficulty of anything _______ he does it personally.
【多选题】设计铣床夹具时,应该满足( )基本要求。
A.
夹具要有足够的刚度和强度。要有足够的夹紧力,夹紧装置自锁性要好
B.
夹紧力要作用在工件刚度较大的部位,且着力点和施力点方向要适当
【判断题】装船机行走机构主要由行走支撑装置、行走驱动装置、行走安全装置三部分组成。( )
【判断题】设计夹具时,夹紧力的作用点应尽量作用在工件刚度较高的部位,以防止工件产生较大的变形。
【多选题】设计铣床夹具时,应该 ( )。
A.
使夹具要有足够的刚度和强度,要有足够的夹紧力,夹紧装置自锁性要好
B.
让夹紧力要作用在工件刚度较大的部位,且着力点和施力点方向要适当
【判断题】What’s proper in one place may be improper in another place.