I am pretty sure the answer is C.
friction is the resistance that one surface or object encounters when moving over another. Due to gravity pulling everything down things need to friction in order to move
i hope this helps :/
Answer:
it make your immune system build up from the strain your puting on you body
Explanation:
excercise is good for you and builds muscle and blood cells
Answer:
Spiral galaxies consist of a flat, rotating disk of stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.
Elliptical galaxies have smooth, featureless light-profiles and range in shape from nearly spherical to highly flattened, and in size from hundreds of millions to over one trillion stars. In the outer regions, many stars are grouped into globular clusters. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity They are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies.
irregular galaxies were once spiral or elliptical galaxies but were deformed by gravitational action. they are shapeless.