A sling is a device used in().
A sling psychrometer is used to measure().
A sling psychrometer is a(n)().
If the sling bumps()the beams,serious accidents may follow.
The ()(包装货) is loaded and unloaded by cargo sling.
If the sling bumps()the beams,serious accidents may follow.
The proper place()the sling is made up is the square of the hatch.