Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. 听力原文： Exercise is beneficial to your heart. A 22-year study was conducted by doctors in(26)California. They(27)found that people who work at physical lobs experience fewer heart attacks than other people. The active people work all the time at moderated speeds. Their daily routine gives them an adequate amount of exercise and helps them stay in shape. (28)However, machines that Call do heavy labor more speedily are replacing this type of work. (27)