英语听力：探索发现 2012-12-30 冰河新新州 Ice Age Oasis—8

 But how did one man and a spear produce the huge force behind this blow? The answer lies with small bits of ivory like this. They were once part of an atlatl, or spear thrower. An atlatl acts as a sort of catapult, magnifying the strength of a hunter's throw, allowing him to launch a spear up to 200 metres, with enough power to drive the point through a bison skull¹. It's this kind of sophisticated technology that helped these early North Americans to spread throughout the entire continent. 

 

But what else did they find once they reached Florida? Florida's ice age wildlife was remarkably² rich and diverse. There were many familiar animals, normally found further north, but also creatures unique to the tropics. The result was a mixture of species unlike anything we see today and an abundant food source for the human immigrants. 

 

So what produced ice age Florida's wealth of wildlife? Part of the answer comes from the ice itself. 

 

At the peak of the last ice age, massive glaciers³ up to 2 miles thick covered over half the North American continent. The ice destroyed the habitat over which it lay, but it also had a profound impact on regions far away. It created a domino effect that rippled⁴ down the continent.

1 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

2 remarkably   

ad.不同寻常地，相当地

参考例句：

• I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
• He made a remarkably swift recovery. 他康复得相当快。

3 glaciers   

冰河，冰川( glacier的名词复数 )

参考例句：

• Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
• It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）

4 rippled   

使泛起涟漪（ripple的过去式与过去分词形式）

参考例句：

• The lake rippled gently. 湖面轻轻地泛起涟漪。
• The wind rippled the surface of the cornfield. 微风吹过麦田，泛起一片麦浪。