I don’t see any picture of cell
Explanation
Reference not given
Answer:
D
It helps the reader to understand which layers of the atmosphere are most important. Don't cheat
It may be a lake, a marsh, a spring or a glacier. This is where the stream starts. The source is the farthest point of the river stream from its estuary or its confluence with another river or stream. ... The farthest stream is called the headstream or headwater.
The correct option is D.
A natural law refers to a description of natural event that has been proved to be true without exception. Such a law usually generalizes a body of observation but can not explain why the observation occur. An example of a natural law is Newton's law of gravity, he observed that an object thrown up usually come down but can not explain the reason behind this observation.