11. Damaged seeds would on top of water. 12. Cholera is  caused by.

13. Like synthetic fibre , plastic is also a  .

14. Metals react wih acids to produce   gas.

15. The Fire produced by oil cannot be controlled by.

16. Migratory birds fly to far away places because of       changes.

17. cell without well organised nucleus  are called   cells.

18. Time period of a pendulum depends on its .  

19. The size of pupil becomes when you see in dim light.

20. Shrillness of a sound  is determined by the   of vibration.​

11. Float

12. Bacteria

13. Polymer.

14. Hydrogen.

15. Water.

16. Climatic.

17. Prokaryotic.

18. Length.

19. Large.

20. Frequency.

Explanation:

11. Damaged seeds would float on top of water. This is because they are typically empty and as such lacking in any form of nutrient.

12. Cholera is caused by bacteria. This bacteria is scientifically called Vibrio cholerae.

13. Like synthetic fibre, plastic is also a polymer.

14. Metals react wih acids to produce hydrogen gas.

15. The Fire produced by oil cannot be controlled by water.

16. Migratory birds fly to far away places because of climatic changes.

17. Cell without well organised nucleus are called prokaryotic cells.

18. Time period of a pendulum depends on its length. Thus, the time period of a pendulum is directly proportional to its length i.e as its length increases, the time period also increase.

19. The size of pupil becomes larger when you see in dim light.

20. Shrillness of a sound is determined by the frequency of vibration.​ A shrill sound refers to a type of sound that is typically sharp, high pitched and as such has higher frequency.

answer; /// the correct )

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.