Evolution of new diseases I think is the answer you're looking for.
Making of faces - this is the correct answer in this case because the movement of either food or blood or beating of the heart for that case don't involve voluntary muscle movement. On the other hand, when're making faces, we're deliberately deciding whether we want to make a face and what face we want to make. hope this helps :)
Biological hazards are substances that pose a threat to living things.
~ThePirc
Answer:
Gray matter
Explanation:
The gray substance (or gray matter) corresponds to those areas of the central nervous system of grayish color mainly composed of neuronal somas and axons lacking myelin along with glial cells (neuroglia).