Convection is cool things sinking and hot things rising. So for example when you have the heat on the upstairs is always hotter than downstairs because heat rises and continues to go in circles until the whole house it heated up.
The answer is D. Because planting nonnative species is bad for the area because the plants that normally grow there have to compete with that new species then.
Malfunction might lead to organ diseases, and might alter the body metabolism.
i would say D. ! :) let me know if this is correct
In this case the objects must be touching