When floodwaters recede affected areas are often

Câu hỏi: When floodwaters recede affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials, such as sharp debris pesticides, fuel and untreated sewage.

A to cover completely with thick layer of some thing

B to expose to open air comfortably 

C to provide someone with a protective layer 

D  to dig out something hidden for long