背景：两世纪以前，T半岛变成了T岛，和大陆之间的关系被截断了。
现在，T岛上的向日葵变得比大陆的向日葵要矮几十厘米（注意这里的比较对象）。
控制因素：T岛的气候变得比之前更干了。结论：是气候的变化让T岛的向日葵变矮了，

推理模式是果因推理。

A：T岛上其他植物的生长情况，和逻辑链无关。
B：过去和现在的数量比较，和向日葵变矮无关。
C：大陆的环境在这两个世纪中没有显著的变化，以至于大陆上的向日葵长高了40cm。--取非：大陆的环境在这两个世纪中有显著的变化，以至于大陆上的向日葵长高了40cm。取非后削弱了原结论，说明T岛的花相对而言矮了不是因为本岛气候变化导致的，而是大陆气候变化导致大陆的花长高了，相当于给出一个他因。正确
D：T岛的土壤缺乏让花长高、生存的必要营养。--取非：T岛的土壤不缺乏让花长高、生存的必要营养。取非后排除了一个可能的原因，加强了原来的结论，所以不正确。
E：40cm的差距是不是两地的花唯一的差距？和逻辑链无关。

we have no reason to assume that the existence of a rule implies compliance with that rule.

be to do：
作表语，to do表示尚未发生，如：The problem is to find a solution.  
作情态动词，
(1)表示将要作某事，如；
He is to have a holiday. 
After dinner they were to go to a movie. 
(2)表是应当/可能等，如：
You are not to smoke in this room.房间里不准吸烟。
You are to be back by 10 o’clock. 你必须十点以前回来。

if were to表与将来的情况相反

Shirla argues that because professional figure skaters who compete against amateur skaters will already have had success on the amateur circuit, the professionals will have an unfair advantage over the amateurs.
Ron, points out that this means that it has been a long time since the professionals have had to meet the more rigorous technical standards of the amateur circuit.
Ron is countering Shirla's reason for thinking that professional figure skaters would have an unfair advantage.

D 原文没提到heavily，程度

which跳跃修饰，hearings复数

请问：with but also这个用法没有问题吗？but also是不是要求前面必须出现not only，一起组成not only……but also……的固定搭配？

解析错了。。应该是是否能准确判断这个人是否会投票。

Because the passage focuses on five historically important literary figures, it is most relevant to the study of history and literature.

果因推理另一个评估方向是给出一个更合理的解释

"an organic relationship between the self and the cosmos of which only intuition and imagination can properly take account"

A，make cars more efficient now than before=make cars more efficient now than they were before，意思是使得同一批小汽车现在比过去更有效率。

C，make cars more that are more efficient now than those before
生产的是不同的小汽车，比较的是不同小汽车的车的一个性质--燃油效率的高低，生产比之前的小汽车更具燃油效率的小汽车。
改成make small cars more fuel-efficient now than those before也是可以的

Choice B presents a broad topic that includes the matters discussed in all four paragraphs of the passage.

in addition to/besides/as well as是介词，虽然不是并列词，但语意上要求句子里有成分可以与其并列。
A/B/C的possibilities只能与主句的名词并列，表达的意思是：除了（减少）可能性以外，还能减少风险。
E，besides preventing与主句的动词并列，表示除了预防癌症，还可以减少风险。

B，possibilities控制力弱，不接to do

and/or：预防癌症是在癌症发生前预防；阻止癌症是在癌症发生后阻止它扩散，二者不能同时发生，不能用and

with独立主格 是可以表达因果关系？

As written, the phrase Like the one reputed to live in Loch Ness . . . compares the one to what comes immediately after the comma directly after the river, namely inhabitants of the area around Lake Champlain. That is surely not the intended comparison.

The intended meaning of the sentence, of course, is that the “sea monster” reputedly sighted at Loch Ness is like the “sea monster” reputedly sighted at Lake Champlain.

The phrase plausible though it sounds modifies the noun that comes immediately after the comma, namely, the weakness of the hypothesis. As a result, the sentence says that the weakness itself is plausible. It is reasonably clear, however, that the sentence is intended to indicate that the hypothesis sounds plausible, not that the weakness does.
D. This version appropriately describes the hypothesis itself as plausible.

如果要用助动词来省略性表达前面出现过的一个谓语动词，被省略句子必须与前面句子的时态一致。如果两者的时态不一致，后面的从句不能用省略表达。
eg.:
Right: I have never seen an aardvark, but my father has.
Wrong: I have never seen an aardvark, but last year my father have.
Right: I have never seen an aardvark, but last year my father saw one.
除非不会导致歧义，如：
Our cars were designed to inspire envy, and they do.

不同时间状语下物体性质than的比较，前句有时间状语时，后句可以省略只保留时间状语；前句没有时间状语时，后句需要补出主谓（可以使用助动词等省略式），以避免比较对象上的歧义。如果前句隐含的时间是now等，后句也可以省略只保留时间状语。后句使用了比较对象+助动词时，其时态与前句是不一样的，是可以的。

would have to know是不很肯定的语气，其表达的是have to do的内容只是一个假设，并不是真的"必须"，而have to表达的意思是，要做的事情非常重要，"必须"去做。在本题中两种含义都合理，因此没有必要做这样的区分

B. The construction has four times the tensile strength of steel has is idiomatically incorrect. The correct construction is has four times the tensile strength of steel.
the comma after steel breaks up the sentence in such a way that only the great tensile strength of white cedar is offered as an explanation of the buildings' ability to withstand earthquakes, rather than both white cedar's tensile strength and the timber frame's flexibility.