The only way that they can preserve their history is to recount it as sagas -- legends handed down from one generation of another.These legends are useful because they can tell us something about migrations of people who lived long ago, but none could wri

他们保存历史的唯一办法是将历史当作传说讲述，由讲述人一代接一代地将史实描述为传奇故事口传下来。

The modern weather models work with a grid of points of the order of sixty miles apart,

现代气象模型以一个坐标图来显示，图中每个点大约是间隔60英里。

And although no period or place in American history has been more absurdly romanticized, myth and reality did join hands in at least one arena, the conflict between the individual and encroaching civilization.

虽然在美国历史上没有任何时期或地区像西部拓荒时期那样被荒谬地浪漫主义化了，但神话和事实至少在某一个舞台上共存，也就是存在于个人与渐渐闯入的文明这两者的冲突之中。

and that is what all patients demand of their doctors----to be cured at no inconvenience to themselves.

病要治好，但不要太麻烦。

For our purposes, we are concerned only with one kind of cost----

就我们的目的而言，我们只关心一种费用-

Although an ocean wave gives the impression of a wall of water moving in your direction,

虽然，海浪给人的印象是一堵由水组成的墙向你压过来，