A、R12、R22 B、R22、R12 C、R134a、R12 D、R12、R134a
A.甲對(duì); B.乙對(duì); C.甲乙都對(duì); D.甲乙都不對(duì)
A.氫氣 B.氮?dú)?br /> C.氦氣 D.氧氣