What characteristics make white dwarf stars different from main sequence stars?

Eventually, a main sequence star burns through the hydrogen in its core, reaching the end of its life cycle. At this point, it leaves the main sequence. Stars smaller than a quarter the mass of the sun collapse directly into white dwarfs. White dwarfs no longer burn fusion at their center, but they still radiate heat.

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

substitution is the answer in this case