题目

请先阅读短文，掌握其大意。然后从各小题所给的A、B、C、D四个选项中选出可以填入相应空白处的最佳选项，并将其填到答题卷的相应位置。（每小题1分） A passenger (乘客) told an air hostess (空姐) that he needed a cup of water to take medicine when the plane just took off. She told him that she would bring him the  41  soon.        Twenty minutes  42 , when the passenger’s ring for service sounded, the air hostess realized it at once. She was kept so busy that she  43   to bring him the water. Therefore, the passenge如图所示的四种现象中，属于光的折射现象的是（　　 ）