Answer:

activity 2

1.yes

2.yes

3.no

4.yes

5.no

Explanation:

act3

1.gold,silver and iron

2.no prove

3.metal iron

4.yes.Because we must keep in mind energy cannot be conserved absolutely, we must look to the origin of this energy in the means of food, and calories in particular, that the human body consumes as the source of this heat energy through metabolism.