Help me with all of these please

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

Resperation is a way to release carbon back into the atmosphere

Veronica and her little sister, monique, are playing on a seesaw. if veronica weighs 75 pounds, and monique weighs 60 pounds, which statement is true?