读下面某地等高线图，回答1—3题。

1、图中甲地表示的地形部位是[ ]

A．山谷

B．盆地

C．山顶

D．鞍部

2、图中A、B两地的相对高度是[ ]

A．150米

B．200米

C．300米

D．400米

3、图中B地在A地的[ ]

A．北方

B．南方

C．西方

D．东方

There are some health problems that, when       in time, can become bigger ones later on.

A．not treated

B．not being treated

C．not to be treated

D．not having been treated