From ____ early age he was interested in plants. He ____ (study) agriculture in college and as a young teacher he began experiments in crop breeding. He thought that the key to ____ (feed) people was to have more rice and to produce it more quickly. He thought there was only one way ____ do this-by crossing different species of rice plant, and then he could produce a new plant which could give a ____ (high) yield than either of the original plants.