解释下这个句子的结构和意思 看不懂

题目

解释下这个句子的结构和意思 看不懂
While 13-year-olds are the most likely group to start a friendship with a parent over Facebook,with more than 65 percent of those friendships being started by the child,people in their twenties are the least likely,starting just 40 percent of the friendships with their parents,Facebook says.

答案

13岁左右的儿童最有可能和他们的父母在facebook上成为好友—有65%的好友关系是这些儿童发起的.而二十几岁的人与父母在facebook上成为好友的几率最少—只有40%的人与父母是好友.--来源于facebook
结构：主句：people in their twenties are the least likely(省略to start a friendship with a parent over facebook).with more than 65%...by the child和starting...with their parents都是伴随状语.while 13...over facebook是伴随状语从句.