Sensory receptors is the answer I found
Solving problems with science means that to solve the problem the scientific method is used. This method includes observing, research, hypothesis , test and conclusion with a help of lot high level theory.
Without science there is not strict process to follow in order to resolve the problem end get to a solution.
Epithelia are classified by the number of cell layers and the general shape of the cells
Answer:
1. Before: carbon dioxide After: Oxygen
2. Oxygen
3. Chloroplast