Which of the following is an example of a positive feedback? a. when your body is cold and triggers shivering to warm your body up
b. insulin's reducing blood sugar
c. withdrawing your hand from a painful stimulus, like a broken glass
d. the formation of a platelet plug during blood clotting

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

a compound light microscope is used to magnify objects in steps.  

hope it