A.錨固劑直徑 B.錨固劑凝固時(shí)間 C.錨固劑長(zhǎng)度60mm D.錨固劑長(zhǎng)度600mm
A.穩(wěn)定煤層 B.比較穩(wěn)定煤層 C.不穩(wěn)定煤層 D.極不穩(wěn)定煤層