How could you use a microscope to determine whether a specimen is a living or nonliving thing

Whether living or non living:
When you put a sample of tissue under a microscope, if u can see a cell membrane, and can identify some cell structures like nucleus, mitochondria, vacuoles etc. , it was living, if not, its a non living thing.

However some cells don't have a nucleus( eg. prokaryotic cells), but all cells have a cell membrane or some sort of protective covering to contain the cell's insides. 

To check if your specimen maybe-once living, maybe-still living "something", is living, get a look at it through an electron microscope - thats the best microscope ever- and see if the mitochondria's making any ATP( adenosine triphosphate, source of energy for most organisms), if it does, its living. If not, non living. :)

The speed of  sound:   sound travels  at different speeds depending on what it istraveling through. of the three mediums (gas, liquid, and solid)  sound waves travel the slowest through  gases, faster  through  liquids, and fastest  through  solids.