Thelinewiththemoststretchis().
A. manila
B. nylon
C. polypropylene
D. dacron
在室外地面高压设备上工作,应在工作地点四周装设遮栏,遮栏上设置适当数量的()标志牌,标志牌必须朝向遮栏里面。
A. “止步,高压危险!”
B. “在此工作”
C. “禁止合闸,有人工作!”
D. “由此进出”
ThemainadvantageofaChinesestopperovertheonelinestopperisthatit().
A. willnotjamonthemooringline
B. isstronger
C. iseasiertousewhenunderheavytension
D. issafertousewhenunderheavytension
Themetal,teardrop-shapedobjectsometimesusedwithinaneyespliceisa().
A. grommet
B. reinforcement
C. spliceform
D. thimble