<span>There are two major theories that will explain on research on colour vision. They are 1. the trichromatic theory also known as the Young-Helmholtz theory 2. opponent-process theory. These two theories explain processes that operate at different levels of the visual system.</span>
<span>1. c) Exposure would weaken the body’s immune system and leave it unable to fight future infections.
</span>2. <span>c) Excess amounts are removed by the kidneys and excreted along with urine.</span>
