这个在选项里写的很清楚啦，给方案一个额外的好处是没用的，必须说没有坏处。

我想知道and that they的那个that指代的是啥？

deny sb sth,permission to do,permission on n

后面的could have 表示可能已经破坏了地球的臭氧层，以及晒伤了我们石器时代的祖先（而不是晒伤了我们）进一步表明这个辐射是在过去发生的，而不是一个通常的状态，所以这里emitting作exploded的伴随状语是可以的。

B，that a star as bright as the full moon exploded into view 340,000 years ago, emitting……，主体是that a star exploded, emitting修饰exploded，意思是在爆炸时发出能破坏地球臭氧层的辐射
E，that exploded 和that emitted会误会是在修饰moon

1、固定搭配：forbid sb to do sth; prohibit sb from doing sth禁止做某事
2、主语和状语的区别：授予特权这个动作就像颁布法令一样是没有地点的，墨西哥应该作主语，而不是在墨西哥授予特权

考察as ... as ...的平行结构。be well known for因……而闻名，被人熟知
B，became well known as much for ... as for ...，分析里面的as……as结构，became well known as much as，well作副词修饰known时已经表示程度，如A do sth as well as B，不再加much，所以as直接放在well前面， became as well known for ... as for ...

background：对于一个camp里面挖出来的动物骨头鉴定，发现camp起源于1605-1755之间
P: 因为site里没有发现欧洲贸易货物，而欧洲商人只在1620年代以后才在这块地区活动-> C：camp的出现不会晚于1630年

choice b, 所有被可靠得鉴定晚于1620年以后出现的camp，都找到了欧洲贸易品。correct
choice c, 第一批出现的欧洲贸易品会被认为特别珍贵因此好好保存下来。-> would have been只是说应该是这样， 依然没有排除missing，destroyed的可能性

1、if引导条件状语从句,从句可为真实条件从句,也可为虚拟条件从句。如为真实条件从句,谓语用陈述语气,表示“假使”“如果”,if+一般现在时，sb do/may/can/will do sth，后者的区别在于：do表示确定发生，may表示可能发生，will表示将来。如：If Sophie eats pizza, then she becomes ill. VS If Sophie eats pizza, then she may become ill. VS If Sophie eat pizza tomorrow, then she will become ill.

2、if引导的条件不可能发生的，用虚拟语气，强调过去没有发生用if past perfect(had done), then conditional perfect(would have done)；强调现在不可能发生用if past, then past future(would do)，或 if were to, then past future；强调未来不可能发生用if should do, then past future。

3、助动词were,should,had可以移至主语前倒装,if可省略。
如：If Sophie had eaten pizza, then she would have become ill.=Had Sophie eaten pizza, then she would have become ill
If Sophie were to eat pizza, then she would become ill.=Were Sophie to eaten pizza, then she would have become ill
If it should rain tomorrow, I would stay at home.=Should it rain tomorrow, I would stay at home.

n=2这个情况需要考虑

choice B的问题在于：其实这个plan没有真正解决让电动汽车难以在commuters中间推行的困难（ unsuitable for extended trip), 同时还让电动汽车变得更加昂贵了（徒增劣势）

background: 导致电动汽车不能被commuters接受的原因是因为电动汽车无法适用于偶尔的远途出行。
Goal:为了让电动汽车对于commuters更受欢迎. Plan: 厂商对于每开电动汽车1000公里的用户，提供免费3天租赁普通汽车

* it will make the electric vehicles even more expensive than they already are (= worse);
WHILE
* ... doing nothing for the existing problem; i.e., the new plan still doesn't make electric vehicles suitable for extended trips (= no change in the problem).

so, that plan makes another thing (the price) worse, while not affecting the original issue.

E，heat transferred between them occurs slowly,要么是do sth slowly, 要么是sth occurs slowly，heat transferred表示动作，不表示某件事，表示某件事用heat's transferring或the transfer of heat

P: 不受专利保护的药物在大众承受的起的价格，受专利保护的药物更加贵-> C :只有对维持生命的药物的专利保护废除了，这种药物在未来才有可能变得可得。
choice d, 只有专利允许制药公司获得高收益，公司才担负得起新药的研发工作。 correct

DE,when……时，人们节约能源，那不与其他人比较时，这些人就不节约能源了？when用在此处错误。

E,what appears that，that引导宾语从句，先行词在从句中要充当成分。