A.1.5倍 B.2.5倍 C.3.5倍
A.5-15mm B.15-25mm C.1-10mm
A.本開(kāi)關(guān) B.上一級(jí)開(kāi)關(guān) C.本開(kāi)關(guān)上一極開(kāi)關(guān)都行