4) Which of the following events can change the
conditions of an ecosystem?
a. A rise in temperature.
b. A natural disaster.
c. The introduction of a new animal species,
d. All of the above.
E olhat is a herbivore?

Option D) All of the above.

Explanation:

The ecosystem is made up of living and non-living component relating with their environment. i.e in an ecosystem, plants and animals relate with the food nutrients, climate and weather conditions, soil structure etc

Thus, all of the conditions: a rise in temperature; natural disaster like flooding; the introduction of a new animal species like a predator will definitely change the previously stable condition of an ecosystem.

i'm assuming that the correct answer is indeed the first one/ "a"..

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year