题目

完形填空。根据短文内容，从A、B、C、D四个选项中选出可以一个能填入相应空格内的最佳答案。When I was in Grade 7. I had no interest in history. I didn't listen carefully in class and couldn't   1  my homework on time. So I didn't do well in this   2  .In the second term, there came a new history teacher. She was young and humorous. But I  3     had no passion (激情) for history. One day, she said, “We’ll have a test in the afternoon. Please prepare for it. Since I was not good at history, whenever I  4   a history exam, I had to cheat (以下对痰的形成起主要作用的是（   ） A．肌肉                    B．腺细胞和纤毛       C．气管软骨              D．毛细血管