USING THE GRAPH BELOW, ANSWER THE QUESTION. Q. There are 3 different populations in this graph. Mark two statements below which are most likely true.
1. Population A and population C probably have a predator-prey relationship
2. Population B and population C probably have a predator-prey relationship
3. Population A is not likely harmed nor helped by populations B and C
4. Population A is often harmed or helped by populations B and C.

2 and 3

Explanation:

1 is incorrect because A does not seem to have a predator-prey relationship  but C does

2 is correct because of the increase and decrease does indicate the predator-prey relationship B and C have

3 is correct because the over time the population remains the same since it is not harmed by B and C

4 is incorrect because if A was harmed by B and C, the population should decline.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.