041.
Joe Jones was born in 1931. As a boy, he had a dream of becoming a doctor. But in 1948, when he was 17, he had to work to help to support his family. Joe worked in construction, on the railroad, and served in the army for over ten years. Then he worked in his hometown of Philadelphia for twenty years. But he still kept his dream of going back to school. In 1979, at the age of 48, Joe decided to make his dream come true. He finished high school and became a student in the Community College of Philadelphia, where he took all the math courses he could. In 1981, after a degree at the Community College, he was admitted to study computer in the University of Pennsylvania. In 1986, Joe completed his work on his master's degree. At the age of 56, Joe was studying for his doctor's degree. His dream was coming true.

答案解析：
(1) 正確答案為A。根據But in 1948, when he was 17, he had to work to help to support his family. 但是在1948年，他17歲那年，他不得不去工作以貼補家用。因此可知，約翰不得不去工作的時間是1948年，因此A項正確。
(2) 正確答案為C。根據he was admitted to study computer in the University of Pennsylvania. 他進入賓夕法尼亞大學學習計算機。因此可知，他在賓夕法尼亞大學學的是計算機，因此C項正確。
(3) 正確答案為B。根據Joe Jones was born in 1931. 喬·瓊斯生于1931年。以及In 1986, Joe completed his work on his master's degree. 1986年，喬完成了碩士學位。可知，喬是在55歲時完成的碩士學位，因此B項正確。