Which is one piece of information that astronomers use to calculate the age of the universe? dark energy
the age of rocks on Earth
the current motion of inner planets
patterns of background radiation

it would be c. xylem.

a few examples of ethical concerns involving genetically engineering of humans include

-privacy of genetically tested people

- potential side effects

-long term effects

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

just finished the test, the answer is d, greg is the least cost-effective because he charges the most for the project