1. Planet and their moons are the examples of

2. Which of them is the most important machine

3. What is called universal solvent

4. The living things which eat meat are called

5. Which of them is best solvent

6. The power house of cell is called

7. A machine makes the work

8. What is the speed of sound in air

9. Which organisms are called producers

10. The main components of environment are called

11. What are tissues

12. The percentage of nitrogen in the air is

13. The living things which eat both plants and meat are called

14. Which gas is used in photosynthesis

15. Animals cells can not prepare their food because

16. which statement is true

17. A solution consisting of two substance is called

18. Sound can not travel in vacuum because

19. Which of them is energy of the sun

20. The living things which eat Grass are called