隧道的附属建筑物包括（）。
A.人行道
B.防、排水设施
C.量测、监控
D.通风
E.照明
参考答案：A, B, C, D, E
在煤气区域作业，便携式CO检测仪低于（）ppm时可以工作。
A.120
B.24
C.50
D.300
If children are asked to help with housework, they will feel needed. ______, they will learn to take care of themselves.
A．On the contrary
B．In a word
C．That is to say
D．What’s more
