题目

Young people and older people do not always agree. They sometimes have different ideas about living, working and playing. But in one special program in New York State, adults and teenagers live together in a friendly way. Each summer 200 teenagers and 50 adults live together for eight weeks as members of a special work group. Everyone works several hours each day. They do so not just to keep busy but to find meaning and fun in work. Some teenagers work in the forests or on the farms near the village. Some learn to make things like tables and chairs and to build houses. The adults teach them th构成人体细胞的主要成分中含量最多的是（ ）A. 水 B. 蛋白质 C. 无机盐 D. 维生素