How many half-lives occur in 4 hours?
A. 1
B. 2
C. 3
D. 4

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.

What is the difference between a meteoroid and a meteor?

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.