A.在20℃时,钢瓶内的压力约为60个大气压
B.液态二氧化碳从钢瓶中喷出时变为气体
C.喷出后其体积比原来大450倍左右
D.变成气体的同时放出大量的热
Which of the following isn't mentioned in the three advertisements?
A.Marriage.
B.Male or female.
C.Education.
D.Working experience.
A.80r/min
B.100r/min
C.120r/min
D.140r/min