You want to find out about new developments in road materials for extremely cold conditions. since this is a complex topic, you want to break it down into its main concepts to identify keywords that could you search. are the keywords below examples of the essential concepts from this topic?

Roads (or highways, streets)

Surface materials (or concrete, asphalt, pavement)

Cold (or frost, ice, Arctic)

Explanation:

Roads (or highways, streets)

Surface materials (or concrete, asphalt, pavement)

Cold (or frost, ice, Arctic)

The above keywords makes it easy to understand the core concepts of the development in road materials for extremely cold conditions. This keywords provides us the information about what type of roadways are to be developed using what kind of materials and in what type of environment.

Thus the answer is

Roads (or highways, streets)

Surface materials (or concrete, asphalt, pavement)

Cold (or frost, ice, Arctic)

your answer would b. the missisipi river

hope i you : )