Which is the best way to judge the cooking or holding temperature of food

What is an important step to prove something is valid or not? determining the reliability observing research testing

Write a paragraph about why the respiratory system is important and we need to breathe easily. (guys i really need ) x(

Melanocytes and keratinocytes work together in protecting the skin from uv damage when keratinocytes a. provide the melanocyte with a protective shield against abrasion b. maintain the appropriate temperature so the product of the melanocyte will not denature c. maintain the appropriate ph in order for the melanocyte to synthesize melanin granules d. accumulate the melanin granules on their superficial portion, forming a uv-blocking pigment layer