A.400-420 B.400-460 C.250-270 D.250-300
A.丁腈橡膠 B.氯丁橡膠 C.西苯橡膠 D.順丁橡膠
A.0.38 B.0.38-11.4 C.11.4-22.8 D.22.8-60.8