A、支撐式液壓支架或支撐掩護(hù)式液壓支架,及時(shí)支護(hù)或滯后支護(hù)
B、支撐掩護(hù)式液壓支架或掩護(hù)式液壓支架,及時(shí)支護(hù)或滯后支護(hù)
C、支撐式液壓支架或支撐掩護(hù)式液壓支架,及時(shí)支護(hù)或超前支護(hù)
D、支撐掩護(hù)式液壓支架或掩護(hù)式液壓支架,及時(shí)支護(hù)或超前支護(hù)
A、0.1~0.2
B、0.2~0.3
C、0.2~0.4
D、0.3~0.5