Answer:
#1 false its difficult but also possible. #2 true and #3 False. the Salivary gland in the mouth make 1.5 liters a day
Fossil fuel + oxygen gas -------> carbon dioxide + water + heat
Ok here we go:
Science starts with observing which leads to hypothesis, which is tested by experiments.
The other two i am not sure of. Hope i was a help to you. One thing you can do to figure out the other two is google: "what type of science includes medicine and envirnmental science", and do the same for the other one.
This is true because all living organism experience life.