中气相色谱法测定公共场所空气中一氧化碳时，使用的色谱柱为长2m、内径为2mm、内装TDX-01碳分子筛的不锈钢柱。
参考答案：对
对子积累。
“秋月白”对“ ____________________”
“水绕”对“ _____________________”
“雨中山果落”对“____________________”
Some people get in touch with each other by mobile phones__________ others keep contact with each other by e-mail.
A．when
B．before
C．while
D．since
