A.防霜 B.防水 C.防塵 D.防凍
A.120mm B.100mm C.80mm D.60mm
A.單層防護(hù)棚 B.單層防護(hù)網(wǎng) C.雙層備護(hù)網(wǎng) D.頂部能防止穿透的雙層防護(hù)廊