"Introduction of non-natives always cause great harm to the environment." Non-natives don't always cause damage and/or harm.
Answer:
The control group? (IDK)
Explanation: Isn't the control group the group that has all the factors that the experimental group has, except for the factor that's being changed?
The correct answer is c. muscularis mucosa.
-17 this is the answer becuase you subraction
