where句型：
    (1) where 引導的定語從句
    例：This is the house where he lived last year. 這就是他去年住過的房子。
    (2) where 引導的狀語從句
    例：Where there is a will，there is a way.有志者事竟成。
    He left his key where he could find.他將鑰匙放在易找到的地方。
    I will go where I want to go.我要去我想去的地方。
    (3) where 引導的表語從句
    例：This is where you are wrong. 這正是你錯的地方。
    注：引導狀語從句的where= 介詞+the place where (定語從句)
    例：Go where(ver) you are most needed.到最需要你的地方去。