根据短文内容及首字母提示，填写所缺单词，使短文意思完整。
Mr Johnson didn’t have an experience of travelling in a plane before and he read a lot a air accidents, so one day when a friend offered to take him for a ride in his own small p , Mr Johnson was very w   about accepting. Finally, however, his friend promised him that it was very s , and Mr Johnson boarded the plane.
His friend started the engine and began to taxi(滑行) onto the runway of the airport. Mr Johnson h the sound of the engine. He was extremely frightened and c  his eyes.
After a minute, he opened t  again, looked out of the w  of the plane, and said to his friend , “ Look at the people down there. They look as small a  ants, don’t they?” “Those are ants,”answered his friend. “We’re s  on the ground.”