Humans breathe through bronchi. what structure do insects have for breathing?

a.
gills

b.
tracheae

c.
skin

d.
lungs

The rate at which molecules water and oxygen can enter a cell is determined by the-

This aquarium exhibits biotic and abiotic factors in an aquatic environment. one of the abiotic factors is

During the winter, this species of fox has white fur, but in the summer, it has brown fur. what environmental change may have lead to this fox's fur color? snow cover increase in sun's brightness volcanic eruption global warming