The lion and bobcat......
Answer:
Element
Explanation:
Element is a pure substance that cannot be broken down.
Answer:
Arteries carry oxygenated blood away from the heart. Veins carry the blood back to the heart. Veins contain valves that ensure blood flows in only one direction. Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.
Explanation:
There are 11 major organ systems in the body.
Answer:
By the numbers, humans produce a lot of food—enough to provide every person on Earth 2,750 calories per day, exceeding almost all dietary recommendations.
There’s one glaring problem, however: Humans aren’t producing enough of the right food.
When researchers at the University of Guelph in Canada broke those calories down into different food groups, they found a shortage in production of the most important foods. In the long run, with the global population expected to balloon to about 10 billion people by mid-century, this could cause some serious problems.
Explanation:
