题目

某船开始看见灯塔在南偏东方向，后来船沿南偏东方向航行30 n mile后看见灯塔在正西方向，则这时船与灯塔的距离是          n mile。 答案：That old woman lives alone. But she refuses others’ help and does everything by ______.A. her B. herself C. she D. hers