Is your school life that of other teens?这个句子中that是什么用法

Is your school life that of other teens?这个句子中that是什么用法 这个句子中that是什么用法? is that your school的答语是什么? is that of 的用法是什么? 请问is that of是什么用法? 这个句子中两个that的用法 Know that each day of your life is a gift. that +of 是什么用法 It is this that is life.这个句子是否正确? ''Is that your backpack''这个句子怎么翻译 Is that a photo in your school? is that your school的答语