In the theory of plate tectonics, how should you picture the earth? A. The plastic atmosphere floats on the lithosphere. B. The continents are held in place by the solid core below. C. The crust is like pieces of a puzzle, slowly moving. D. The mantle is like pieces of a puzzle, slowly moving.

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d