Freida wants to model the way atoms move when a substance changes its state. To do this, Freida makes a pyramid of marshmallows. Then, she knocked down the pyramid causing the marshmallows to fall.

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks

Islam and the arabic language spread throughout north africa in the 600s primarily through a. african traders b. american colonists c. european explorers d. middle eastern armies select the best answer from the choices provided

High human population have had a negative effect on what issue? a. demand for consumer goods b. ability to staff armies c. business profits d. biodiversity