对错畸形种族演化的叙述，不正确的是（）。 A.颌骨逐渐退化缩小 B.颅骨逐渐增大 C

     Young people and older people don't always agree with each other. They sometimes have different ideas
about living, working and having fun. 1. _____ Each summer 200 teenagers and 50 adults live together for
eight weeks as members of a special work group. Everyone works for several hours each day. The purpose
of this program is not just to keep busy. 2._____ Some teenagers work on the farms near the village. Some
learn to make furniture and to build houses. The adults teach them these skills.
     There are several free hours each day. Weekends are free, too. 3._____ Others sit around and talk or sing.
Each teenager chooses his own way to spend his free time.
     When people, live together, rules are always necessary. In this program the teenagers and the adults make
the rules together. 4._____ They ask,"Why did it happen? What should we do about it?"
     One of the teenagers has this to say about the experience," You don't only think about yourself. You learn
how to think about the group."