Astronomers use stars to measure distances in space because stars have known brightest and regular patters of change. Without using the scientific method, how were scientists able to develop this system? A: They observed and measured the properties of many stars over time.
B: They traveled to space and measured distances between stars.
C: They based their information on the ideas of the smartest scientists.
D: They built stars on Earth to perform experiments on them.

You're doing research for a public essay on alternative medicine. which of the following sources has the most reliable information? a.a post on a social networking site about the undesired side-effects of different alternative medicinesb.a recent government report comparing the results of alternative and contemporary medicine for a specified diseasec.an anonymous article on a medical website that claims the success of alternative medicined.a 2003 study conducted by a medical research center about the effects of alternative medicine