Read the passage carefully and choose the best answer to each question out of the four alternatives

Atoms of carbon - hydrogen and oxygen are put together to make molecules of sugar -a carbohydrate food substance. The carbon comes from carbon dioxide gas in the air. Air enters through holes, called stomata, in the plant's leaves. The hydrogen and oxygen come from water. The water is taken up from the soil by the plant's roots. The light energy is trapped by a special chemical called chlorophyll. Chlorophyll is green and gives green plants their colour. The gas oxygen is left over at the end of photosynthesis and goes into the air.