Read the passage and fill in the blanks with proper words.(在短文的空格内填入适当的词，使其内容通顺，每空格限填一词，首字母已给)

    George Stephenson was born in 1781 in a poor f. He had to start working when he was o eight. When George was fourteen, he became his father's helper. It took him a lot of time to learn about the engine. O holidays he often took it to pieces and studied each piece carefully. Soon he became a very good worker though he couldn't read or w. He began to learn English letters when he was seventeen years old. Every day after he did twelve hours' hard work, he walked a long way to have lessons from a young school teacher. On his eighteenth b , he wrote his name for the f time in his life. George was the i of many things. The train was the greatest one among them.