Answer:
The chemical reaction is sped up.
The activation energy is lowered.
Explanation:
When enzymes are added to a chemical reaction, they lower the activation energy needed in the reaction.
In return, that also speeds up the chemical reaction, since less energy is needed to start it.
Enzymes do not stop chemical reactions, and enzymes can also be reused, so they are not used up.
So, the first and third statements are correct.
