A.20%~30% B.30%~40% C.40%~50% D.50%~60%
A.由買產(chǎn)品轉(zhuǎn)向賣服務(wù)B.由賣服務(wù)轉(zhuǎn)向賣產(chǎn)品C.什么都不賣
A.干拌砂漿B.砂漿C.砂石D.混合砂漿