How do changes in the environment affect an ecosystem ?
(5-7 sentences)

There are many ways the environment changes an ecosystem. First, temperature can completely affect an ecosystem. This is important because if an ecosystem gets too warm or cold, the organisms living in there can die off since they aren't made to live in severe conditions. Secondly, weather can also affect an ecosystem by raining, wind, or natural disasters. This is important to an ecosystem because if it rains too much in an ecosystem that needs to stay dry, than the organisms could die. Finally, migration could also affect an ecosystem. Even though this seems odd, it surprisingly changes a whole ecosystem. If predators migrate to the ecosystem, than the organisms are at risk because they are prey and could be eaten. Clearly, an ecosystem can be affected by many things.

(side not you can change this how you want and this is 9 sentences)

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers