【单选题】Condition of self-lock for screw is .A.lead angle ≤ equivalent frication angleB.lead angle ≤ frication angleC.lead angle ≥ frication angle D.lead angle ≥ equivalent frication
A.
lead angle ≤ equivalent frication angle
B.
l ead angle ≤ f rication angle
C.
l ead angle ≥ f rication angle
D.
l ead angle ≥ e quivalent frication
【单选题】西餐宴会还讲究( )原则,同一桌上席位高低以距离主人座位远近而定。
【简答题】What 's the first camera angle ?
【单选题】What’s the problem if the first person adjusts the angle?
A.
The work can’t be finished at all.
B.
The second person can’t match it.
C.
The third person can’t match it.
D.
The boss don’t want to do that.
【简答题】什么是早期胃癌?并列举其肉眼和镜下的类型。
【简答题】请列举至少5个具体的对称加密算法,并用一两句话简单描述。