26. Suggest any one way in which the use of solar energy helps in the protection of the environment.

27. Why is a ventilated improved pit latrine (VIP) left without a cover?

28. How do some people become passive smokers?

29. Draw a prop root system.

30. Name any one crop with a root system similar to the one you have drawn above.

31. What causes an echo?

32. Why does a stone sink when it is put in a bucket full of water?

33. Give any one way through which worms enter our bodies.

34. Mention the instrument used to measure the temperature of a human body.

35. What is the process by which seeds grow into seedlings?

36. State any one use of an axe in a home.

37. Give any one reason why white objects are seen easily even at a distance.

38. Give any one way in which people benefit from bees.

39. Which bone in the human skeleton protects the brain?

40. Give any one characteristic which is common in all the invertebrates.