research身后不需要加介词
while是连词，身后应该加完整的句子（表伴随状语时可以加分词短语），不能只加介词短语。
句末出现的状语从句while he lived in France会就近修饰一个句子（定语和状语均具备这个修饰原则）

enough和so不应连用
so…that和such…that均为正确的表达方式，但是so…such…that是不正确
由于原文中整个句子是以一个独立主格开头的（with），且本选项中该独立主格中没有分词（也没有形容词，只有一个定语从句），所以该选项不满足构成独立主格结构的要求（独立主格不能由定语从句构成）

分号一般被用于连接两个或几个独立的分句，但在本题中其和逗号的用法相同，连接了平行的对象。

many people are turning to stockbrokers for help to buy stocks that easily could have been
这里的 could have been 时态错误，人们不能现在去找股票交易员去买之前可以容易被买的股票
"Could have " + participle is always past-
They could have had significance.
He could have been the captain.
easily作为副词要放在离其形容的动词越近的地方越好

产量 production 是不可数的， 41 million tons中的tons是计量单位，不是复数名词

A of B, C 结构里面 C可以是B的同位语

Although typically introduces a subordinate clause, which has a subject and a verb,but here there is no subject and "sighted' is not a complete verb.

When you say "THE other" you imply one of two things: either certain other things (eg books) that you've previously specified (which we haven't in this case) or ALL other things of that type, which is also not what's going on here.
The implication here is that there are SOME other infections

takeaway:
if a sentence contains a COMPOUND NOUN (X and Y), you CANNOT use a pronoun to refer to just X or just Y, unless you use "the former" or "the latter" to make the distinction explicit.

有没大神可以解答这题？

题干--- 方案推理 goal-- improve response rate ; method-- target marketing 问加强
错误B： 并没有说明这些公司的成功是因为定向投放， 也没说投放效果
正确 E： E 取非后 target marketing并不会提高response rate 所以无用（削弱）

risk of causing cancer NOT risk for causing cancer

C选项强调了whenever扩大了这项conclusion应用的范围，同时也表达的soon after这和5s没有本质区别，因此选择C。D除了5s没有更多的信息

B-> the airline would take some losses and then gain them back by charging higher fares for a while. If competitors try to undercut the airline, they'll simply slash fares again for a while to drive out the competition and then repeat the cycle.

promise in / of keeping are just not idiomatic=> "promise to its customers to keep" is the correct version. This leaves us with A and B.

E说最终野花在nursery被养殖，可以达成目的（减少野花的采摘），如果不刊登文章-》野花卖的少=》就没有钱去做新技术研发->就没有nusery养殖-》没有最终目的的实现。

学渣傻瓜发: 第一个字母有5个可能（可能的字母有5个），第二个有4个，第三个只有2个可能（重复C), 第四个3个，第五个2个，第六个1个。相乘等于240

B选项：完整的搭配是“so…that…”，此选项缺少“that”。此外，“can be indistinguishable”表达出的字面意思为“可以是难以辨别的”。但“经济变化是缓慢的”这件事导致的结果直接是“经济变化 是 难以辨别的”，而不是 “可以是”。

牛逼！

The phrase "as varied as" indicates some kind of comparison, so what are you comparing? What is it that is actually varying here? The noun 'countries" before the phrase and the three specific countries listed after the phrase. When you're comparing, you need the things you're comparing in parallel format.

So: "countries" on one side and "China, the Netherlands, and Hungary" on the other. Proper, parallel comparison.