Down here, during the Ice Age, our cousins faced many new challenges. 在冰河时期 我们的表亲在这里面临许多新的挑战
They have no choice but to back down 它们别无选择 只得退下
cave lions can bring down the very largest of prey. 能够捕食这种最大的猎物
who passes her knowledge down the generations. 由其将知识代代相传
but he can't stay down here forever. 但它不可能永远躲在下面
His time down here is limited by how long he can hold his breath. 它在水下的时间 受限于它能屏住呼吸的时间
Sulfur-rich dust poured down as acid rain. 富含硫的尘埃倾泻而下 形成酸雨
To make matters worse, the rock debris starts to rain down. 更糟糕的是岩石碎片 开始如雨点般落下