Mine Supports And Strata Control - Study Mode
[#76] Which prop can serve a long life for sand stowing faces.
Correct Answer
(B) Friction
[#77] It is that load, which is set by a setting device, imparted by an yeilding prop.
Correct Answer
(B) Setting load
[#78] Timber bar errected on to the coal pillar . . . . . . . .
Correct Answer
(B) Sides
[#79] The prop is erreeted in flat seams
Correct Answer
(B) Vertical
[#80] Freshly exposed roof after blasting is effectively and quickly supported by
Correct Answer
(C) Roof bolts