Can somebody me with these questions? i need answers asap

19. 11,000g/m2
20. 40g/m2
21.
a. As the pyramid goes up the g/m2 gets smaller since they slowly run out of food and will compete with each other.
b. No since the bottom is smaller but otherwise it follows the same pattern after, it is like that since there is less plants or plant like creatures in the oceans

water is constantly moving across the earth. The water is strong enough to break down soil in tiny pieces. What’s happening is a process called erosion. Erosion is: the process of eroding or being eroded by wind, water, or other natural agents.

"the problem of soil erosion".

Water also carries sand and moves it around, this obviously changes the shape of the earths surface!

Explanation: