1.It is＋adj.＋for sb. to do sth. As teenagers grow， confused with the changing world both inside and outside of them. 随着青少年的成长，对自己无论是体内还是体外的状态变化感到困惑，这对他们而言是正常现象。

Ⅲ.重点句式

it is normal for them to become