i think that before the Krebs cycle begins, pyruvic acid, which has three carbon atoms, is split apart and combined with an enzyme known as CoA.
The answer is; A gopher snake occupies a burrow made by the desert rat
Commensalism involves a relationship between two organisms where one benefits while the other is unaffected. In this case, the gopher snake gets from the burrow made by the desert sake. The desert rat is unaffected (does not benefit or lose) by this action by the snake.
Surface waves cause most the the damage
Cells create tissues which create organs which make up systems so i believe the answer is D i hope this helps :)