Answer for brainiest :)

D

Explanation:

Well, animal cells use simple sugars, like glucose. The simple sugars are the only ones small enough to pass through cell walls.  We use ATP to access the energy in the sugars. Cells can either use a aerobic system (using oxygen) or an anaerobic system to metabolize sugars. Humans generally use the aerobic system although in some cases our cells are forced to use the anaerobic system.

they each offer a fresh glut of resources to the organisms that can arrive and exploit them. as individuals and new species continue to appear, they actively and passively alter the environment. competition for shared resources increases, local abiotic and biotic conditions shift, and the relative abundances of species change accordingly. the process is called ecological succession, and it is one of the earliest and most well-known concepts in ecology.

a chair, a bed, and a toothbrush

explanation:

i was told this before by a teacher, so yeah