Answer:Because they keep on repeating.
Explanation:
Answer:
Explanation:
human activities should no be more than the capacity of ecosystem
we should pay attention to carrying capacity of eco system
another one i don't no sorry for that
hope you like my answer and hope it helps you
Histamines are chemicals released by the body as an allergic response.They help the body by reacting when their are "intruders" so when enters, histamine acts as a messenger and sends out a signal for the body to create a reaction helping to get rid of teh intruder through some type of reaction.
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray Group 2 alkaline earth metal, fifth-most-abundant element by mass in the Earth's crust. The ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.[5] Free calcium metal is too reactive to occur in nature. Calcium is produced in supernova nucleosynthesis.