近似数0.030有效数字的个数有（ ）
A．4个
B．3个
C．2个
D．1个
0.030的有效数字是3，0．
故选C．
To be honest, it was what he meant ______what he said that made me so angry.
A．more than
B．rather than
C．other than
D．less than
什么叫节流？为什么节流后温度下降？
