A、He worked in a supermarket for tuition. B、He helped someone to learn to read. C、He gave single mothers the help that they need

Last summer I went through a training program and became a literacy volunteer. The training I received, though excellent, did not tell me how it was to work with a real student. When I began to discover what other people’s lives were like because they could not read, I realized the true importance of reading.
     [16]My first student Marie was a 44-year-old single mother of three. In the first lesson, I found out that she walked two miles to the nearest supermarket twice a week because she didn’t know which bus to take. When I told her I would get her a bus schedule, she told me it would not help because she could not read it. She said she also had difficulty once she got to the supermarket because she couldn’t always remember what she needed. Since she did not know words, she could not write out a shopping list. Also, she could only recognize items by sight, so if the product had a different label, she would not recognize it as the product she wanted. As we worked together, 1earning how to read built Marie’s self-confidence, which encouraged her to continue in her studies. She began to make rapid progress and was even able to take the bus to the supermarket. At the end of the program, she began helping her youngest son, Tony, a shy first grader, with his reading.
    As a literacy volunteer, I learned a great deal about teaching and helping others. In fact, I may have learned more from the experience than Marie did.
16. What did the speaker do last summer?
17. How did Marie use to find the goods she wanted in the supermarket?
18. How was Marie’s study during the summer?