简单题！错选a
比较选线ac，多斟酌（并不是越短就越对。）这道题是大意了。
small cars more fuel-efficient now than at any time in their❌
small cars that are more fuel-efficient than those at any other time in✅
两者比较才发现明显是c更正确，多用选项间比较

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

I'm going to make air conditioners quieter. --> I'm going to modify existing air conditioners so that they make less noise.

I'm going to make quieter air conditioners.
I'm going to make air conditioners that are quieter.
--> I'm going to make a new model that makes less noise.

A is like the first one of these, so it doesn't make sense in context.

又错了。。

it/they同物指代，that/those是异物指代，指代同类别不同物

it和they是同物指代！

D,E 的语义就不对， DE的意思是， 现在比以前制造更多的fuel-efficient small cars？ 原意应该是现在的车比以前more fuel-efficient

形容词修饰歧义，如：We have even more efficient engines than before.是more efficient还是more engines？
C，定语从句中的关系代词 that 或 which 既可以指代单数先行词，也可以指代复数先行词。如：
These are the parcels that are going to be posted. 这些是准备要寄出的包裹。
D，now作时间状语与另一个时间状语比较时，可以省略，因为从语意可以看出是指的现在这个时间。

cd错选d
more应该修饰f-e，而不是更多小车，重点在f-e，所以选c

it/they同物指代，that/those是异物指代，指代同类别不同物

any other time

还是要理解句字意思：The sentence, as stands, is confusing. It implies that the 'small cars' are now more fuel efficient than they were in the past. That is the manufactures took an old small car and said, "hey let's make this more efficient." Clearly, however, the small cars today are different from those in the past.we can omit (A), (B).

B项的they是完全指代，所以错。C的those是部分指代，对

我有一个问题 at any time in history 这有必要加上other 吗？毕竟now不在history 里面啊，我觉得这说at any time in the past 是一样的

any time 不等于 any other time .只能用any other time,否则就把now也包括进去了。

此外，A中核心比较对象是make efficient这件事情，所以要比较对等就得后面也是一件事情。DE中比较的是现在比以前可以产更多汽车，不符合题意，要比较的话也只需要用now 和in any other time 作比较就可以了

①more+adj.+noun==>本身就是一个很有歧义的表达 排除DE
②more ... than at any time // or // more ... than at any other time
any里就包括了现在的时间
eg：...offer evidence more dramatic than what has yet been discovered of the close evolutionary.==>EVIDENCE HAS YET BEEN DISCOVERED 包括了句子开头的EVIDENCE ，所以要用最高级比较合适

at any time 和 at any other time

Choice E is still wrong, because it doesn't say "any other time".
"Any time" includes now. So, according to choice E, they can make more cars now than at any time"”"”including now!
Nonsense. X can't be more than X.

at any time错误
more fuel-efficient small cars有歧义，more可以修饰cars和fuel-efficient

A B E重的at any time 不对 没有把现在排除在外，应该是at any other time