Why are gills, a heart, and a closed circulatory system a much more efficient way of getting oxygen to all the cells than that of insects?

Due to fast transportation of oxygen, waste material and nutrients.

Explanation:

Gills, a heart, and a closed circulatory system are more efficient ways to provide oxygen to all cells than that of open circulatory system of insects because in the closed circulatory system blood transfers is faster than open circulatory system, thus oxygen, nutrients, and wastes transport is also very fast so we can say that closed circulatory system is more efficient than open circulatory system.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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