在吊升作业前,应对吊索和吊具进行检查,保证钢丝绳无打扭、破股、断丝、压伤,吊带无破损,吊点、吊环无开焊,吊环连接紧固,否则导致什么后果?
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木电杆外表皮不应全部剥除,杆身应无硬伤,劈裂,表面有高出2厘米以上的残留节疤。
A. 正确
B. 错误
Which two statements are true about simple views?()
A. Views can be created as read only.
B. Views are data segments like tables.
C. Views can be created on the basis of more than one table.
Data manipulation language (DML) operations cannot be performed on views.
电动轮汽车的转向是常流式动力转向,阐述其工作原理?
高档电动、电子玩具:可定期用95%酒精棉球擦拭孩子经常抚摸的部分。
A. 正确
B. 错误