A.延長(zhǎng)層間養(yǎng)護(hù)時(shí)間 B.縮短層間養(yǎng)護(hù)時(shí)間 C.延長(zhǎng)層問間歇時(shí)間 D.縮短層間間歇時(shí)間
A.10~30s B.10~20s C.20~30s D.10~40s