A.汽水,燃料,電氣 B.汽水,化學(xué)水處理,電氣 C.汽水,燃燒,電氣 D.工業(yè)水,汽水,電氣
A.10° B.20° C.30° D.40°
A.2mm B.5mm C.10mm D.8mm