Answer:
You could use one to see if that $210934879207344329 dollar "living" wood table is living or not. It could also be used at hospitals...
Sorry never heard of that "key" in my life...
Chemical changes are not usually physical so you can’t see them I guess so I would put D
Answer:
because light is also the source or heat
heat and light come together in many cases
The answer is: the amount of the saliva samples must stay consistent while the amount of starch must vary.
The amount of the saliva samples must stay consistent because amylase, present in the saliva, is the independent variable which affects the dependent variable - the amount of starch. So, amylase will do its job while remaining surface area of the starch will depend on the starting amount of the starch.