The confusion of costs with rates persists partly because labor rates are a convenient target for managers who want to make an impact on their company's budgets. Because labor rates are highly visible, managers can easily compare their company's rates with those of competitors.

But labor costs and labor rates are not in fact the same: one company could pay its workers considerably more than another and yet have lower labor costs if that company's productivity were higher due to the talent of its workforce, the efficiency of its work processes, or other factors.

changes to the compensation system may appear to be simpler to implement than changes to other aspects of an organization, so managers are more likely to find such advice from consultants palatable.

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？