VOA慢速英语:The Secret Life of Roots

短语讲解：

1. All of the roots are rolled up and dried up so they do not touch the floor.

roll up 卷起; 卷成圆筒形
例句：Don't roll up the shutters.
别拉百叶窗。
dry up 枯竭; （使…） 干涸
例句：The sun will soon dry up the roads.
太阳很快就会把道路晒干的。

2. Susan Pell takes hold of a soybean plant and explains why farmers depend on roots. 

depend on 依赖; 相信; 信赖
例句：The tides depend on the pull of the moon.
潮汐是月亮引力作用的结果。

3. You just really kind of wonder are we going to be able to sustain agriculture.

be able to 能够
例句：We shall not be able to furnish additional copies.
我们将不能提供额外的副本。