B) They permit exchange between the external atmosphere and the circulatory system.
Oceans often get oil and toxic waste dumped into them as a bit of a "cheat" to cheaply dispose of waste. This harms the ocean life greatly. A leading cause of dumping into the oceans is the expense of getting rid of used oil. If a city were to allow residents to dispose of these things at no cost to them, there would be no need for people to dump it into the ocean. This will reduce the harm to sea life.
Meiosis is the type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells this process is required to produce egg and sperm cells for sexual reproduction
I'm not in high school but I think it's ten or 100
