Fill in the blanks:
1. Arteries carry ........................ blood and veins carry ........................ blood.
2. ........................ is the excretory organ present in earthworms.
3. Kidney is made up of tiny structures called ........................ .
4. The liquid part of the blood is called ........................ .
5. ........................ is a process of giving blood to a needy person.

Fill in the blanks of the following paragraph using just two words – arteries and veins

___(a)___ carry oxygen-rich blood from the heart to all parts of the body and ___ (b)___ carry carbon dioxide-rich blood from all parts of the body back to the heart. ___ (c)___ have thin walls and ___ (d)___ have thick elastic walls. Blood flows at high pressure in ___ (e)___. Valves are present in ___ (f) ___ which allow blood to flow only towards the heart. ___ (g)___ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form ___ (h)___.