What economic system is characterized by an exchange of one product for another

currency

barter

loan

free market

Which of the organism obtains its energy from dead or decaying matter? A. Groundhog B. Bacteria C. Daisy D. Human

Which of the following best describes why the sun is so important to us? A. it quickly purifies air that becomes polluted B. It is the major source of energy on Earth. C. Without it, all the water on Earth would evaporate.

How does ocean currents and jet streams affect the weather

Which individual is at the least risk for osteoporosis? thin, elderly male male weight lifter in his 20s petite asian female thin caucasian female in her 40s?

Which sphere is part of the carbon and water cycles, but absent from the phosphorus cycle? A. Biosphere B. Atmosphere C. Hydrosphere D. Cryosphere Answer: B - Atmosphere

What is it called when you interpret the things you observe

Rubidium-87 has a half-life of 48.1 billion years. After how many years is there 25 percent parent isotope and 75 percent daughter isotope contained in the object?

In what layer are convection currents found? A. Continental crust B. Inner core C. Asthenosphere D. Oceanic crust

The major organs which control acids and bases in the body are: Select all that apply.

What is it called when some traits require more than one gene to be fully expressed?