How do you the explain the changes in population of organisms through time?​

What are levels of ecology and how can we remember them

In a leaf, dermal tissue a) stores food b) stores carbon dioxide c) releases oxygen into the air d) transports water from the roots

If a force of 40 newtons moves a cart a distance of 9 meters, the work done is nm. if the same force moves the same cart three times that distance, the work done is nm.