1 What is the original source of energy for most ecosystems?

A. grass
B. humans
C. the sun
D. heat

C. The sun

Explanation:

The sun provides energy for the plant to do photosynthesis. Since all animal species depend on plants qnd the sun helps the plants, the sun is the original source of energy.

answer: accepted answer: aquatic animals use the oxygen dissolved in water to carry out respiration. since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore the rate of breathing in aquatic animals is much faster than it is in terrestrial animals.

explanation: