8. In developing countries, you are most likely to find biomass used A. to generate electricity.
B. for manufacturing.
C. as a source of hydropower.
D. for heating and cooking.

In developing countries, you are most likely to find biomass used for heating and cooking.

i believe the answer would be b. hope it : )

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.