Answer: B. Semicircular canals
Explanation: Receptors of equilibrium are located in the middle part of the oval-shaped bone labyrinth located in the inner ear. This membrane labyrinth has three bony channels that contain perilymph in it. In them again lie the semicircular membrane channels and contain endolymph and containing receptors for equilibrium. Thus the purpose of the ear is not only good hearing but also a sense of balance.
sunlight is a reactant in photosynthesis
Atoms are the smallest unit.
Answer: Diseases are caused by a biological agent.
Germ theory of disease, the currently accepted theory of disease, says that many diseases are caused by microorganisms. These microorganisms are biological agents, too small to see without a microscope, they invade humans and animals to be able to grow and reproduce. These "Germs" can be protists, bacteria,fungi, viruses, prions, or viroids.
