旋挖钻机作业地面应坚实平整,作业过程中地面不得下陷,工作坡度不得大于()。
A.1°
B.2°
C.3°
D.4°
参考答案:B
Critics of the Wright brothers thought that the idea of a flying machine was totally preposterous.
A.attractive
B.boring
C.absurd
D.immoral
杀菌机V84检测电眼作用().
A、检测顶水阀是否开启
B、防止出现酸碱进入平衡缸
C、防止料液从V84排出
D、防止杀菌机管路旁通导致的设备故障