题目

Young people are often unhappy when they are with their parents．They __1__ that their parents don't understand them．They often think their parents are too __2__ with them．Parents often find it difficult to __3__ their children's trust and they seem __4__ how they themselves __5__ when they were young． For example，young people like to do things without much __6__．It's one of their ways to __7__ that they have grown up and they can __8__ any difficult problems．Older people worry __9__．Young people don't like their plans to be changed．So when you want your parents to let you do 抛物线y2=8x的焦点到双曲线x2-y23=1的渐近线的距离是（　　） A、12B、3C、1D、32