简述用示踪气体技术检测井巷风量和漏风的过程？
参考答案：
1）释放量的确定
2）释放示踪气体
3）采样
4）气体分析
下列哪种病毒易发生潜伏感染（）
A.乙型脑炎病毒
B.水痘-带状疱疹病毒
C.流感病毒
D.乙型肝炎病毒
E.脊髓灰质炎病毒
His parents wouldn't let him marry anyone _____ family was poor. [ ]
A. of whom
B. whom
C. of whose
D. whose
