Which one of the following conditions requires immediate medical attention?
a. bleeding from the head after a fall b. skin abrasions after sliding into home base c. muscle soreness after running a 10k d. black-and-blue marks on the shin

In summing we use which law of motion

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

Waste is deposited into in thin layers which are then compacted and covered with soil.