that for most of the year they would be unable to cross it. 它们一年中大部分时间都无法穿越这里
The bats left Mexico a few days earlier to escape the heat of summer 蝙蝠数日前离开墨西哥以躲避酷暑
and are on their way north to the southern United States. 正向北飞往美国南部
But birds are not the only animals to benefit from the presence of the cacti. 不过鸟并非唯一从仙人掌那里 获得好处的动物
the saguaros bloom at night to attract visitors. 弁庆柱在晚上开花 吸引了不少拜访者
When full, a saguaro stem can store up to five tonnes of water 吸饱水后 弁庆柱的茎干中 已储存了5吨左右的水
and that's enough to see it through many months of drought. 这足以帮助它们度过几个月的旱季
are ready to take full advantage of it. 准备充分利用雨水
and the pleats on its trunk enable it to expand rapidly. 茎上的皱褶使之能迅速膨胀
animals and plants have to be ready to make the most of it. 所有动植物都必须 做好准备尽量地利用它们