Answer: Parasites
Explanation:
Both tapeworms and lice depend on a living host to survive. The relationship between the parasite, tapeworm or lice, isn't mutual. The parasite only benefits from the relationship, because the host provides them with plenty of nutrients. In some cases, tapeworms and lice can carry diseases and infect the host. So, there is your answer and goodluck!
Muscle strain and soreness after axercise
Answer: Gasses are exchanged across the alveolar membrane.
The exchange of gasses takes place across the alveolar membrane of the lungs. Our respiratory system are composed of nose, pharynx, larynx, trachea, bronchi, and lungs (alveoli) where gas exchanges between the blood and external environment by diffusion. Moreover, during the gas exchange, the oxygen enters the blood while carbon dioxide enters the alveoli.
