Answer: A closed circulatory system and an excretory system consisting of tubular nephridia
Explanation:
The best answer is D because construction would be bad for the environment and take up space on the soil that is trying to be preserved. Also, for C, planting only one crop type in soil is not very beneficial to the soil at all. IT is best to plant multiple crops in the soil and move the crops to different parts of the soil each year when planting them.
3 atoms (O3) Ozone is the triatomic form of oxygen. Oxygen isn’t the only thing we breathe, we also breathe nitrogen and a whole bunch of other gases. The difference between oxygen and ozone is ozone is o3 meaning it has 3 oxygen atoms instead of just one. I really hope this helped!
The exoskeleton of an arthropod is chitin.
