化工装置用气动差压变送器按其所测量的差压来分，一般有（）、（）、（）、（）、（）五类。
参考答案：微差压；低差压；中差压；高差压；大差压
汽油的爆炸浓度下限为()。
（A）0.8%
（B）1.1%
（C）1.27%
（D）1.3%
The reform project ______ by Mr. White ______ at the meeting now.
A．put forward, is discussed
B．has been put forward, is being discussed
C．is put forward, is discussed
D．put forward, is being discussed
