SECTION - GENERAL SCIENCE 41. The process by which green plants make their own food is called? A. Diffusion B. transpiration C. Photosynthesis D. Circulation E. Commensalism 42 The class of food that gives us energy is called A. Protein B. Carbohydrates C Vitamin D. Mineral Salt E. Roughages 43 Barometer is an instrument used to measure A. Pressure B. Temperature C. Humidity D. Sound wave E. Wind Speed 44. 45. 46. 47. 48. 49. 50.