A. in wet placesB. close to the heatC. away from chemic……

单项选择题It is more economical to use （）, because of their greater strength and longer useful lives.正确答案A

A. nylon ropes
B. manila ropes
C. sisal ropes
D. wooden ropes

单项选择题Natural fiber rope is made （）the fibers of different plants.

A.up
B.from
C.of
D.with

单项选择题Wire rope needs （）care than hemp and manila.

A.good
B.well
C.better
D.best

单项选择题（）is the strongest and the most elastic of all the synthetic fiber ropes.

A. Hemp rope
B. Wire rope
C. Nylon rope
D. wood rope

单项选择题Nylon rope is the strongest and most elastic of all the （）ropes.

A. synthetic fiber
B. natural fiber
C. wire
D. wooden