1. By addition of what food becomes soft and fine

2. The largest artery is

3. The rate of flow of charge is called

4. Human heart has ...............chambers

5. Sound can not pass through

6. Bile is released by

7. Which circuit is used in domestic wiring

8. The lightest part of atom is

9. What is the unit of frequency

10. which of the following is not used in human respiratory system

11. Water is essential for

12. In which waves particles of medium move perpendicularly

13. Where are pollen grains located in

14. There are ...............major habitats.

15. The reverse process of peristalsis is called

16. Food for algae is

17. What is the name of our Galaxy

18. What is the mode of  transferring of heat for energy of sun reaching  us

19. Blood is carried from lungs to heart by

20. flowers are .................part of plant