Q: Answer the question

Scientists measured the patterns of spectral lines given off by distant galaxies and concluded that almost all of these galaxies are moving away from Earth. What did the scientists observe directly?

A: a shift toward longer wavelengths of light

Q: Answer the question

Which rapid changes can be caused by storms?

A: landslides and flooding

Q: Answer the question

Which is a feedback mechanism the human body uses to maintain homeostasis?

A:
perspiring to lower the body temperature