题目

The food we eat seems to have great effects on our health. Although science has made great steps in making food more fit to eat, it has, at the same time, made many foods unfit to eat. Some research has shown that perhaps eighty percent of all human illnesses are related to diet and forty percent of cancer is related to diet as well. Different cultures are subject to certain illnesses because of the food that is characteristic in these cultures. That food is related to illness is not a new discovery. In 1945, government researchers realized that nitrates(硝酸盐) and nitrites(亚硝酸盐),茗居小学四年级师生215人去春游，其中35人乘坐中巴车，其余的人乘坐4辆大客车，平均每辆大客车坐多少人？