完形填空。
Mary is worried about her 16-year-old daughter，Sophia．One day，Sophia comes back from a party，upset and unhappy．From then on，she 1 nothing but how to lose weight and become beautiful．She refuses to eat and keeps on2exercise．Sophia has always been a little heavy，so Mary encourages her to go on a diet．She feels that her daughter would 3 more attractive(有吸引力的)if she lost 5 kilograms．However，Sophia has lost over 10 kilograms until now．Her eating and exercising habits are having a harmful effect(影响)on her 4．She is too thin and is often sick．
Her mother is trying to prevent her from going on a diet and 5 weight，but Sophia thinks that she is still too heavy and refuses to start eating as 6．Sophia's mind is full of the idea of looking like a model. Every day she goes to a club to do exercise．Sometimes she 7 her time reading magazines like Fashion&Beauty．The models in these magazines are very thin and beautiful．Sophia says “If I look like these models. I will be happy and the boys will like me．”
Mary feels sorry for having encouraged her at first，because Sophia 8 feels good or pleased with her body．She's afraid that Sophia will never be happy 9 she always compares herself with the models in the magazines．Mary tries to tell Sophia that true 10 comes from the heart．The most ordinary face becomes beautiful when the person is filled with confidence．
，这条光线从BC边射出棱镜后的光线与界面BC的夹角为（ ）