The main function or the excretory system is to eliminate from the body
ОА. oxygen
OB
energy
OC.
disease
OD waste

Aprimary producer stores 9,000 kcal. in the energy pyramid, if a primary producer is consumed by a first-level consumer, and that first-level consumer is consumed by a second-level consumer and the second-level consumer is consumed by a third-level consumer, how much energy is stored by the third-level consumer from the primary producer? *