气体分析仪正常运行所需的介质有（）
A.氮气
B.循环冷却水
C.除盐水
D.低压蒸汽
参考答案：A, C, D
He went to school by car this morning.
A．drive a car to school
B．went to school in a car
C．took a bus to school
D．by car to school
现阶段，会计职业道德的主要内容不包括( )。
A．团结协作、尊老爱幼
B．坚持准则、提高技能
C．廉洁自律、客观公正
D．诚实守信、爱岗敬业
