List 4 observations that help to determine whether a chemical reactions has taken place

How does a hydroelectric power plant converts energy into energy.

14. many depressants reduce small muscle control, making it harder for a. you to steer b. your mind to consider complex problems c. the eye to scan, focus, or stay still d. the kidneys to filter alcohol out of the bloodstream

Using data from seismic waves, geologists have learned that earth’s interior is made up of several