VOA慢速英语:White Sands National Monument: A Wonder of Nature

at the bottom of在...之底部

例句：There's a pub at the bottom of the road.
      路的尽头有一家酒馆。

      Carelessness is at the bottom of all great mistakes.
      粗心大意是一切重大错误的根源。

2.About twenty-four-thousand years ago, it rained a great deal in the area.

a great deal很多,大量,…得多

例句：His words caused a great deal of dissension.
      他的话引起了许多争论。

      I can't say the news concerns me a great deal.
      我说不上这消息与我有多大关系。