The shift away from family life to solo lifestyle, observes a French sociologist, is part of the irresistible momentum of individualism over the last century.
【词汇突破】irresistible ：不可抗拒的
momentum: 势头，趋势
individualism 个人主义
【主干识别】the shift is part of the momentum.
【其他成分】away from family life to solo lifestyle 介词短语做定语修饰shift;observes a French sociologist插入语;over the last century状语。
【微观解析】注意对shift进行具体描述时用fromto这个结构。
【难点揭秘】本句同样是对于插入语的识别：observes a French sociologist.= a French sociologist observes
【译文赏析】一个法国社会学家观察到，从家庭生活到独居生活的转变是过去一个世纪以来不可抗拒的独立主义动力的一个部分。