For one thing, the summer heat dried out a lot of the region's vegetation, which is like fire fuel.

首先，夏日的烈阳烤干了这里植被里的水分，使之像燃料一样。

The cows in these dairies spend most of their adult lives inside crowded barns or outside in dry lots with no vegetation.

这些奶牛场的奶牛成年后的大部分时间都在拥挤的谷仓内度过，或者在没有植被的干旱场地外度过。

The most interesting theory is that a massive earthquake changed the course of the rivers so much that a lot of the tributaries dried up.

最有趣的理论是，一场大地震极大地改变了河流的走向，以至于许多支流干涸了。