The myth that labor rates and labor costs are equivalent is supported by business journalists, who frequently confound the two.

句意平行，enhance performance, 不能说enhance preparation, 所以只有enhance和prepare才平行

以however为分界线，however后面为前提和主结论。第一个黑体句是整段话的一个背景，第二个为反驳结论的。

hypotenuse斜边

qualify对应exception!

the ratio of A to B； A & B必须是可比的

直接细节题：They insist that mutations in a behavioral gene must alter a specific normal behavior and not merely make the organism ill。即必须同时满足2点：1）改变特定的正常行为。2）不至于导致器官病变。2个条件中的任意一个不满足就可以判断

choice b,c,d都可以根据原文信息排除掉
choice e, 一项对于神经系统来说是很糟糕的信息来源-> 神经科学家对Shaker是负态度。全文后半段一直在对比neuroscientists和ethologists的差异，又因为ethologists不认为Shaker是behaviour gene, 所以neuroscientist更有可能是认可 Shaker是behavior gene。答案因此是choice a

boldface 1: the Greeks actually adopted alphabetic writing at least two centuries earlier-> 希腊人实际上开始采用alphabetic writing 的时间是在8th Century BC之前更早的2个世纪-main conclusion
boldface 2: they would surely have adopted whatever convention the Phoenicians were then using with respect to the direction of writing，过程中希腊人肯定也继承了波斯人书写的方向-assumption

错选B,没有注意限制pollution emitted by cars.
但是感觉A有一点奇怪,, 比较汽车排放的污染物不应该控制开车次数或者里程这些变量?

ECC通过通电的方法来给大桥除冰，并且电力成本比de-icing成本低。但是建造ECC的成本比传统的水泥成本更高，所以从经济角度考虑没有理由用ECC，问weaken
choice a, de-icing salt会造成桥的腐蚀，大大缩减桥的使用寿命。correct，指出了看似更优方案的一个致命缺陷
choice c, 当到了可能要结冰的天气，冰通常会先在桥的表面形成，随后在和地面接触的车行道上形成。irrelevant，无关结冰的过程
choice e, 如果ECC被用于大桥表面，电流只会在冰即将形成的时候导通。irrelevant，choice e可以解释为什么ECC的电力成本低

C D their和they错误
D E 状从修饰错误

正如my swimming yesterday不能被另一个人重复，他只能重复游泳这个概念。

each of which 修饰 taste cells

Mandate is "Bossy word" so C is only choice, You can not use must, should, may when there is Bossy word, neither "to"

A，but do not grow to be very tall与上一个动词develop平行，native North American grasses do not grow to be very tall
B，without可以是副词，跟在最近的动词allows后面，the root system allows for soil without growing too tall,grow的主语错误
without可以作介词，+noun构成状语，修饰最近的一个动作allows，主语还是错误

请问C选项为什么是that falls而不是that fall呢？that 从句应该是修饰snow, sleet and hail吧？如果有个F选项是把C的falls 改成fall,会不会更好呢？

C选项的that从句修饰三者，falls在这路是不是用的不太好啊

A/B，which指代conquest，丹麦对英格兰的征服这个历史事件是不能被其他国王repeat的，能repeat的是把这件事抽象化成一个achievement，repeat一个类似的成就。
C，an achievement that other Scandinavian kings were not successful at it . 这里的that只能只能引导定语从句，it多余；不能做an achievement的同位语解释说明achievement的内容，一是语意上“其他国外在这件事上不成功”并不是achievement的内容，而是它的一个属性，用定语从句，二是同位语里也不能出现it，不能自己同为自己。
E, kings attempted to repeat the achievement, but without success. but是连词，接介宾短语构成的状语，没有并列对象，属于an exceptional use。

but的用法：
可以做并列连词，表转折；

可以做介词，表示“除了”，如：
Everyone but Jim went to school.
I came last but one in the race. 我赛跑得了倒数第二名。

可以做副词，等同于only，如：
There were a lot of famous people there: Tom Hanks and Julia Roberts, to name but two.

but的其他特殊用法如：
The grasses develop an extensive root system, but without growing too tall.
I had no choice but to sign the contract. 我别无选择，只好签了合同。
He would have played but for a knee injury. 他要不是膝部有伤的话，就上场了