324.New research now suggests that climate shifts have played a key role in nearly every significant tuming point in human evolution: from the dawn of primates(灵长目动物 ) some 65 million years ago to human ancestors rit}ing up to walk on two legs, from the huge expansIon of the human brain to the rise of agriculture.
一项新的研究表明，气候的变化几乎在人类进化中的每一次重要关头都扮演了关键角色：从6500万年前的灵长类动物到人类祖先的直立行走；从人类脑容量的增加到农业的兴起。

六级词汇讲解:

本句的主干是New research...suggests that...。that引导的是suggests的宾语从句that climate shifts have played...；冒号后的内容from the dawn of..to the rise of agriculture对该从句进行补充说明。

shift在句中意为“转变”，该词还可指“轮班”。如：
I don't want to work the night shift.
我不想上夜班。

turning point意为“转折点，关键时刻”。如：
This interview was a tuming point in his career.
这次面试是他事业上的转折点。

dawn原本意为“黎明”，引申义为“开端；萌芽”。如：
They are looking forward to the dawn ofbetter days.
他们期待更好日子的来临。

expansion意为“扩大，扩展”。如：
The board are against a major savings expansion.
董事会反对大量扩充储蓄业务。

英语六级考点归纳

nse、anse和raise这三个动词形似义近，均有“上升；举起；涨高”之意，但存在一定的区别。

rise为不及物动词，没有被动语态，后面不能加宾语，可指具体的或抽象的动作。如：
The -river rises every spring.
河水每年春天都会上涨。
The people wanted to rise against the oppression.
人民想起义反抗压迫。

arise为不及物动词，多用于诗歌或比喻中，常用抽象名词作主语。如：
These problems have arisen as a result ofyour carelessness.
出现这些问题是因为你粗心。

raise为及物动词，要带宾语，有时还指“养育；提出问题”等。如：
The boss decided to raise Bob's salary.
老板决定给鲍勃涨工资。
She raised chickens and pigs.
她养鸡和猪。