阅读下面材料,在空白处填入适当的内容（1个单词）或括号内单词的正确形式
Yuan Longping is one of China's most famous scientists. ____(work) the land to do his research, he considers himself a farmer. Indeed, his sunburnt face and arms and his slim, strong body are just like those of millions of Chinese farmers, ____ he has struggled for the past five decades. When he was young, he saw many people dying of ____ (hungry), which was a ____(disturb) problem in many parts of the countryside. Then, he devoted all his time and energy ____searching for a way to increase rice harvests without expanding ____ area of the fields. In 1973, he became the first agricultural pioneer in the world ____ (grow) rice that has a high output. Now, he remains ____(circulate) his knowledge in many less developed countries to increase their rice harvests. He is quite ____(satisfy) with his life. However, he doesn't care about being famous. He feels it gives him less freedom to do his research. In his view, spending money on himself or ____ (lead) a comfortable life means very little to him. He therefore gives much money to equip others for their research in agriculture.
