A. chemicals, the constriction of the pupil are usually caused by opiates anti-hypertension drugs.
Im pretty sure its
A. Number of Organisms
B. Amount of Matter
A million sorrys if im wrong :(
Meninges are membranes that cover and protect the brain and spinal cord.
There are three layers of meninges: Dura mater (closest to the bone), Arachnoid loosely around the brain, Pia mater is closely attached to the brain and spinal cord surface.
A. Consumers cannot produce their own food source so they have to eat other animals.
C. Rhizobia bacteria "prepare" the atmospheric nitrogen and make it useful for the plant.
Hope it helped,
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