The cutting down of trees
So you know that your measurements are exactly correct.
By determining the density of the object
The answer is B. Cnidarians
Cnidarian body has no left or right side, only tom and bottom surfaces. If you divide cnidarian a about central point, you will get equal parts. So, cnidarians are radially symmetrical animals. This group includes hydroids, jellyfish, anemones, and corals. In all groups, animals have stinging cells on tips of tentacles. They use them to capture the prey. Their name literally means stinging creatures.
B. A persistent neurotoxin is a substance that damages the brain and nervous system