Answer:
Open circulatory system:
Relies on the heart to keep blood flowing
Used in all vertebrates
Sorry thats all i know :)
Answer:
Oxygen
Explanation:
Glucose reacts with water to form carbon dioxide, water and give energy.
Answer:
Population growth, lack of supplies
Explanation:
Urbanization can impact an area, especially population growth. People could be crowded, and that supplies could run out as it is an urbanized region.
