反馈建议 切换旧版 去做题 结束训练
全文精听 逐句精听
句间停顿： 关
  • 关
  • 1S
  • 3S
  • 5S
语速： x 1.0
  • 速度0.8X
  • 速度1.0X
  • 速度1.2X
  • 速度1.5X
  • 速度1.8X
  • 速度2X
始终显示原文
欢迎使用 KMF 精听精研
坚持练习精听，反复听、吃透每个句子，能够快速 提升听力能力
开始精听
或按 「 空格」开始播放

段落1

listen to part of a lecture in an anthropology class.

点击显示原文

隐藏原文=

Okay, now we\'ve discussed how early modern humans used fire to cook food, a development from over 800,000 years ago. But what are some other ways that early humans used fire

点击显示原文

隐藏原文=

Do a pottery, like from clay that they heated up, or tools made out of metal? Uh huh, pottery and metal tools. That\'s a good start.

点击显示原文

隐藏原文=

Now here\'s the interesting thing.

点击显示原文

隐藏原文=

Remember, early humans started cooking about 800,000 years ago, right?

点击显示原文

隐藏原文=

Oh, and keep in mind that on this scale, these numbers are not exact dates.

点击显示原文

隐藏原文=

They\'re more to give us a general time frame for when certain advances occurred.

点击显示原文

隐藏原文=

Anyway, pottery, or the earliest evidence of pottery appeared about 30,000 years ago,

点击显示原文

隐藏原文=

and metalworking was even more recent, only 5500 years ago.

点击显示原文

隐藏原文=

So what do you notice, given these dates, a gap, right,

点击显示原文

隐藏原文=

a pretty big gap between the developments of cooking and pottery making with seemingly no significant developments in the use of fire between them.

点击显示原文

隐藏原文=

Well, that has all changed now thanks to some exciting findings by a researcher named Kyle Brown

点击显示原文

隐藏原文=

while he was working at pinnacle point in South Africa.

点击显示原文

隐藏原文=

Pinnacle point is a stone age site dating from about at least 72,000 years ago.

点击显示原文

隐藏原文=

Brown and his team of researchers found early tools with sharp, fine blades

点击显示原文

隐藏原文=

perfect for tasks such as cutting animal skins to make clothes.

点击显示原文

隐藏原文=

They were of such good quality, they may have even been traded

点击显示原文

隐藏原文=

and these tools were made out of silcrete.

点击显示原文

隐藏原文=

Silcrete is a hard rock made of silica,

点击显示原文

隐藏原文=

and the silcrete tools that were found were dark reddish brown and highly glossy.

点击显示原文

隐藏原文=

But when Brown began searching the areas near pinnacle point,

点击显示原文

隐藏原文=

he couldn\'t find any silcrete that had the same properties as the silcrete tools he found at the site.

点击显示原文

隐藏原文=

The silcrete that Brown found around pinnacle point was yellow and dull.

点击显示原文

隐藏原文=

It crumbled easily and was not good for making tools, so Brown was unable to account for where the silcrete tools at pinnacle point had come from.

点击显示原文

隐藏原文=

That is, until one day, Brown found a large piece of silcrete in what had once been a fire pit

点击显示原文

隐藏原文=

used by the early humans at pinnacle point,

点击显示原文

隐藏原文=

it looked like it might have been accidentally dropped in the fire

点击显示原文

隐藏原文=

or maybe not. Most of the silcrete tools they found at the site were small,

点击显示原文

隐藏原文=

probably made by chipping small pieces off a larger rock. So finding an unusually large piece of silcrete buried in ash.

点击显示原文

隐藏原文=

Could this mean that the silcrete had been heated before being made into tools?

点击显示原文

隐藏原文=

So to test his hypothesis,

点击显示原文

隐藏原文=

brown conducted an experiment.

点击显示原文

隐藏原文=

He collected some yellow silcrete from the area around pinnacle point and heated it in a fire.

点击显示原文

隐藏原文=

He found that not only was it easier to work with, it flaked rather than crumbled,

点击显示原文

隐藏原文=

but it looked exactly like the silk Creek tools he had found at pinnacle point.

点击显示原文

隐藏原文=

The mystery was solved. So why is all of this important?

点击显示原文

隐藏原文=

First of all, the tools that Brown found were from at least 72,000 years ago,

点击显示原文

隐藏原文=

and represent a developmental step in the use of fire between cooking and pottery making.

点击显示原文

隐藏原文=

But more importantly, the process that Brown had to follow to create his replicas of the stone tools was very complex.

点击显示原文

隐藏原文=

First, he had to gather firewood and fuel for the project in advance,

点击显示原文

隐藏原文=

then bury some silcrete and sand and build a fire over the sand.

点击显示原文

隐藏原文=

He had to gradually increase the temperature of the fire over a period of 12 hours,

点击显示原文

隐藏原文=

then maintain a constant temperature for about five more hours, and then let. Let the fire cool slightly so the stone didn\'t crack.

点击显示原文

隐藏原文=

But once he did all this, he was able to create exact replicas of the tools he had found.

点击显示原文

隐藏原文=

This complex process means that these early humans had advanced cognitive abilities,

点击显示原文

隐藏原文=

such as the ability to solve problems and plan ahead.

点击显示原文

隐藏原文=

They also needed to have language, to communicate, to teach each other how to create these amazing stone tools.

点击显示原文

隐藏原文=

Now, some of you might be wondering, could the tools have been burned unintentionally?

点击显示原文

隐藏原文=

They could have been made from unbaked stone and then caught in a bushfire or something later on.

点击显示原文

隐藏原文=

I don\'t know.

点击显示原文

隐藏原文=

I agree with Brown when he said that the greasy, shiny gloss on the thin blades proves that these were heated before being chipped off.

点击显示原文

隐藏原文=
[ < 空格 > ]
当前句 /
/
  • 段落1
  • 第 1 句
  • 第 2 句
  • 第 3 句
  • 第 4 句
  • 第 5 句
  • 第 6 句
  • 第 7 句
  • 第 8 句
  • 第 9 句
  • 第 10 句
  • 第 11 句
  • 第 12 句
  • 第 13 句
  • 第 14 句
  • 第 15 句
  • 第 16 句
  • 第 17 句
  • 第 18 句
  • 第 19 句
  • 第 20 句
  • 第 21 句
  • 第 22 句
  • 第 23 句
  • 第 24 句
  • 第 25 句
  • 第 26 句
  • 第 27 句
  • 第 28 句
  • 第 29 句
  • 第 30 句
  • 第 31 句
  • 第 32 句
  • 第 33 句
  • 第 34 句
  • 第 35 句
  • 第 36 句
  • 第 37 句
  • 第 38 句
  • 第 39 句
  • 第 40 句
  • 第 41 句
  • 第 42 句
  • 第 43 句
  • 第 44 句
  • 第 45 句
  • 第 46 句
  • 第 47 句
  • 第 48 句
  • 第 49 句
  • 第 50 句
  • 第 51 句

+ 创建收藏夹
保存 取消