The answer is; C & E
Building a dam alters the water regime down the dam. The dam also affects fish migration along the river, alters the transportation of sediments by the river downstream, and changes temperatures within the local environment of the dam. These changes, however, the subtle effect the ecosystem around the dam and down the river. The potential energy of the water held by the dam is, however, high and used to produce more electricity.
Not enough info, but I'd go with:
B) hydrogen peroxide
The answer is skin. The skin is also the largest organ in the body and has the most contact with the outside environment. It is estimated that there are approximately 205 identified genera of bacteria alone on the skin. This normal flora of the skin play significant roles in the body such as augmenting immunity.
Answer:
Nitrification.
Explanation:
It is a part of the Nitrogen Cycle. The bacterias can convert ammonia into nitrite and nitrate, these compounds are fundamentally important for all life. They are used for the creation of proteins and amino acids.
I hope this answer helps you.