题目

Joe moved to Canada with his family at the age of 41. There were many stressful(压力重的) days for them in the beginning. Since Joe had no job, the savings(存款) they brought with them were diminishing quickly. One day, Joe went out to look for a job. As he walked, he saw many things on the street that people threw away. Joe could not believe his eyes. “Why would people throw away such things?” he asked himself. Joe saw a “new” television and decided to take it home to see what the problem was.Since he was 12 years old, Joe’s main hobby has been electronics(电子产品). As a 氢气在空气中燃烧时，火焰呈 [　　] A．淡蓝色 B．蓝紫色 C．黄色 D．苍白色