Why do we find discernable tree rings in trees in the northern hemisphere but not near the equator?

*will mark brainliest to first correct answer* photosynthesis led to increasing levels during the later proterozoic eon? a. oxygen b. water c. carbon dioxide d. none of the above

Many animals cannot sweat to maintain a stable body temperature. what is one other way animals can cool down?

Urgent. the table shows the relative blood flow through some organs in the human body that is, the percentage of blood that flows through a given organ, through which organ(s) does all the blood flow? explain the effect of exercise on blood flow to skeletal muscles.