单项选择题
A.射吸式焊炬和高压式焊炬 B.射吸式焊炬和等压式焊炬 C.射流式焊炬和等压式焊炬 D.虹吸式焊炬和负压式焊炬
A.0.1~2 B.0.1~0.2 C.0.4~0.8 D.1~0.2
A.氧气流 B.乙炔气流 C.空气流 D.电弧