1. Which fluid in the human body wets the internal organs?
2. Where does the blood absorb oxygen in the human body
3. Name the two parts of the plant through which gaseous
the air.
4. Why do the walls of the trachea not collapse when there
5. Normally a vein opens into a large or into the heart but
one or more veins in human is/are exceptions to this rul
6. Give reason for- the lung alveoli are covered with blood