In order for chemical digestion to occur, what has to be mixed with the food?

Where are the strongest jet streams located?

What methods do scientists use to predict volcanic eruptions? select all that apply

Asample of a population should be large enough to: a. justify the cost of the items needed for the simulation. o b. include more than half of the entire population. o c. span the full spectrum of a population's genetic variation, o d. generate a very large amount of data.