What role does the mantle play in the rock cycle?

Weathering and Erosion. They are part of the process.
@Google.

Glaciers are an important part of the rock life cycle. The part they play is to break huge rock faces into smaller pieces, as well as to move rocks from one place to another, while grinding them into pebbles and sand.

Yes you are correct use the scientific method

Ok so co(g) is not pronoused that. the only clue is that youpronouse it the oppisote way.