The most numerous cells in the lungs are dust cells, also known by their scientific term of alveolar marcrophages.
These cells are located in any person's lungs and are responsible for keeping your lungs and air pipes clean of any dust particles and other materials that may harm your body. Their role is to destroy any foreign substances, such as bacteria and others.
To find your altitude above sea level, you would use an altimeter to find the altitude.
Since there are no choices, it will be difficult to answer your question.
Let's say these are the choices:
A. The liquid is a pure substance because it is colorless.
B. The liquid is a mixture because its temperature rises.
C. The liquid is a pure substance because it remains liquid when cold.
D. The liquid is a mixture because it has a gas dissolved in a liquid.
your answer is D. The liquid is a mixture because it has a gas dissolved in a liquid.