I'm Yuan Longping. Look at my sunburnt face and arms and my slim strong body and you will think I'm ____ like a farmer than a scientist. In fact I ____(struggle) for the past five decades to help ____(farmer). In 1974, I began to grow a so-called super hybrid rice. This special strain of rice makes ____ possible to produce one-third more of the crop in the same fields.

    I was born into a poor farmer's family in 1931. When I was young, I saw many people go hungry often. So I have devoted myself to ____(find) ways to increasing rice harvest without expanding the area of fields since I graduated from Southwest Agriculture College in 1953. Now more than 60% of the rice____(produce) in China each year is from this hybrid strain. I am circulating this knowledge in India, Vietnam and other less developed countries to increase their harvest. Perhaps you think I am rich. ____(actual) I live a simple life. I care little for money. In my opinion, a person with too much money will have more troubles. I don't want to be famous ____ I prefer to have more time to do my research. In my free time I love listening to music, playing mah-jong and reading. I once had a dream, in ____ I saw rice plants as tall as sorghum and each ear of rice was as big as an ear of corn and each grain of rice was as huge as a peanut. Now I have another dream-to export my rice so that it can ____(grow) all over the world.

赵州桥是世界上现存最古老的一座石拱桥，它建造于（　　）

如果他把金属盒放入10厘米深处的盐水中。你推测压强计左右水面高度差将____ 9．2厘米(填“大于”、“小于”或“等于”)。其理由是____ 。