Almost always
frequently
often
Answer:
D. A reference in a piece of literature to another literary work
Answer:
C.
Explanation:
Pycnocline is a layer in the oceanic body in which the density of water increases with the depth in the ocean. This change in density happens due to the changes in temperature and salinity of water.
<u>Other four words/phrases are related to the process of water purification. The only word which does not fit in the water purification process is Pychnocline. </u>
So, the correct answer is Option C.
