Gravity , Explosion
<u>Explanation:</u>
Nebulae are made of dust and gases—mostly hydrogen and helium. The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. As these clumps get bigger and bigger, their gravity gets stronger and stronger.
Eventually, the clump of dust and gas gets so big that it collapses from its own gravity. The collapse causes the material at the center of the cloud to heat up-and this hot core is the beginning of a star.
Biomes in the temperature zone have been changed the most by human activity.
We can define biomes as the community or group of animals and plants that are distributed or categorized on the basis of common characteristics of environment they are in, five<span> major types of biomes are aquatic, desert, forest, grassland, and tundra.</span>
Lol maybe another time, I am going to do schoolwork in a second
