Objects that are too small or too large, events that occur too slowly or too quickly, and processes that are too complicated or too dangerous are most often represented by .
A.
controlled scientific experiments
B.
specimen collections
C.
models
D.
all of these

Food provides molecules that serve as fuel and building material for all organisms. plants undergo photosynthesis and make their own food. other organisms, like us and the horse seen above, are consumers and eat food. how do all organisms use food as fuel? be sure to include the name of the process in your answer. me.

What re the two main phrases of the cell cycle.

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins