input: OPTIONS:
- hemoglobin
- carbon dioxide
- nitrogen
- oxygen Now, answer this question: Answer the following question given this paragraph: The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava . The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. Q: The superior vena cava and the inferior vena cava are veins that return blood lacking what to the heart? A:
A:
output: oxygen

Answer the following question given this paragraph: Q: Engaging in relatively simple behaviors helps maintain a nearly constant body temperature for organisms classified as what? A:

OPTIONS:
- photophores
- placoderms
- endotherms
- ectotherms

Answer: ectotherms

Problem: OPTIONS:
- hydrogen
- glucose
- helium
- co2
Q: Answer the following question given this paragraph: Carbon dioxide levels in the atmosphere are increasing. Fossil fuel burning is increasing. The rise in fossil fuel burning is increasing the CO 2 in the atmosphere. Q: What gas is released into the atmosphere when fossil fuels are burned? A:
Answer: co2

Problem:OPTIONS:
- resistance
- density
- power
- pressure

Answer the following question given this paragraph: Pressure is defined as the amount of force acting on a given area. It measures how concentrated a force is. Q: What is defined as the amount of force acting on a given area? A:
****
A: pressure

Answer the following question given this paragraph: The velocity of an object can be found from a position vs time graph. On a position vs time graph, the displacement is the vertical separation between two points and the time interval is the horizontal separation. The ratio of displacement to time interval is the average velocity. This ratio is also the slope of the line. Therefore, the slope of the straight line is the average velocity. For the motion pictured above,. Q: The ratio of displacement to time interval is the average what? A:
OPTIONS:
- acceleration
- direction
- speed
- velocity
velocity

Answer the following question given this paragraph: Q: The community of all of the living and nonliving parts of an environment is known as what? A:
OPTIONS:
- habitat
- population
- biodiversity
- ecosystem

Answer:
ecosystem