Each time I wait for the bus, I always take something to read _____ I have to wait. [ ]

A. in case

B. so that

C. now that

D. as though

施工时应遵守有关环境保护的法律法规，并应采取有效措施控制施工现场的各种（）等对周围环境造成的污染和危害。

A.粉尘

B.湿度

C.废气

D.噪声

E.振动