A.80% B.70% C.60% D.50%
A.梁式護(hù)欄 B.柔性護(hù)欄 C.不銹鋼護(hù)欄 D.水泥混凝土護(hù)欄
A.小 B.大 C.相同 D.沒(méi)有結(jié)論