What is the disadvantage of using models to study the food web? A. observations are made from inside the system
B. actual interactions are affected by the models
C. they cannot show all the interactions taking place
D. they cannot help and making predictions about a population

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?