Match these items. 1. protective sacs A. aorta
2. carries blood to the body heart B. chambers
3. carries blood to the lungsC. valves
4. open and close D. pericardium
5. atria and ventricles E. pulmonary

What does the cell nucleus do or, how does it function?

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?