Answer:
C and D
Step-by-step explanation:
A. When you increase the activation energy, the reaction will be slowed down.
The energies that a certain number of molecules have to be equal to or greater than the activation energy so that a chemical reaction can occur. If we increase the activation energy, it is harder for the reaction to occur.
B. Catalysts play a role in lowering activation energy for a reaction to occur more easily. Hence, removing catalysts is not a way to speed up a reaction.
C. Adding more heat or D. Shaking the container holding the reaction are two options that can help the molecules contact one another more frequently, thereby facilitating the occurrence of reactions.