钻眼前，对电钻应该做的检查有（）。
A. 综合保护装置是否齐全、灵敏可靠
B. 钎杆是否平直
C. 电缆是否破皮、漏芯、漏电
D. 螺丝螺帽是否紧固
E. 钎头、钎尾是否合格
飞机对称性检查是指以飞机纵向对称面为基准，测量从对称中心线上给定点到：（）.
A. 两边机翼主起落架安装支点的距离
B. 两边机翼上燃油箱内侧端面给定点的距离
C. 两边机翼上襟翼内侧端面给定点的距离
D. 两边机翼翼尖和水平尾翼翼尖给定点的距离
执行MOO指令后，机床运动停止，重新按“启动”按钮后，再继续执行后面的程序段。
A. 正确
B. 错误
You are troubleshooting an OSPF problem where external routes are not showing up in the OSPF database. Which two options a re valid checks that should be performed first to verify proper OSPF operation?（）
Are the ASBRs trying to redistribute the external routes into a totally stubby area?
B. Are the ABRs configured with stubby areas?
C. Is the subnets keyword being used with the redistribution command?
D. Is backbone area (area 0) contiguous?
E. Is the CPU utilization of the routers high?
微信支付 
支付宝支付