液化气瓶充装过程不得超装，这是由它的（）性质决定的。
A、汽化潜热
B、密度
C、饱和蒸汽压
D、热胀冷缩
参考答案：D
---- What do you think of zoology?
---- In my opinion, zoology is ______ botany.
A．a subject so interesting as
B．as a interesting subject as
C．as interesting a subject as
D．interesting as a subject as
小儿指纹纹色发青，主（）或（）。
