忽略了 a > 0, b > 0, and c > 0

前提：Since nicotine in cigarettes changes brain chemistry, perhaps thereby affecting mood, it is likely that smoking contributes to depression in teenagers.

结论：Those who began smoking within a month of the study's start were four times as likely to be depressed at the study's end than those who did not begin smoking.

请问老师，这个题只能一个一个加起来计算吗？有没有简便算法啊

generally overstated等同于 often overstated吗？generally 和 often 表达的意思不同吧？

"The average number of books per student was 2" means that total of 2*30=60 books were borrowed;
2+12+10=24 students borrowed total of 2*0+12*1+10*2=32 books;
So 60-32=28 books are left to distribute among 30-24=6 students, these 6 are "the rest who borrowed at least 3 books";

To maximize the number of books one student from above 6 could have borrowed we should minimize the number of books other 5 students from 6 could have borrowed. Minimum these 5 students could have borrowed is 3 books per student, so total number of books they could have borrowed is 5*3=15 books. So the 6th student could have borrowed is 28-15=13 books.

Answer: D.

Hope it's clear.

by contrast爱尔兰政府有更大的作用，在日本和印度虽然没有提及，但是这是一种隐形对比。考试中比较常见。谨记

C. an isolation that limited both cultural contact and exposure to European diseases = It limited but did not eliminate contact with other cultural groups.

A. 真正有问题的并不是first sentence中的现象，而是后半句以及下文说的question
C. 并没有区分anoles和其他
D. 并没有解释为什么
E. 并不是morphology和habitat use二者之间的关系

某个国家卖了一半的黄金储量，所以，这个国家引起了(其它国家会做同样的事情并冲击市场）的担忧。

改变了Apalachicola Bay的含盐度，所以夺去了牡蛎的味道并且让它们的变得更小
故rob和decrease要作为伴随状语补充说明alter，与alter为因果关系，非并列关系

C. 公司给受训员工付最低工资，给trainer付更高的工资，当最低工资上涨的时候，trainer的工资也会受影响随之上涨，所以这个政策影响的不止是那些低于5.5的受训员工，还会影响trainer的工资，weaken了 a small proportion

C. 与reform activities无关
D. demonstration：示威游行，文中并未提到
E. 原文：conferred moral standing on the party = enhance the moral standing of the party，正确

However, most historians have underestimated the extent and significance of women's political allegiance in the antebellum period.
低估了女性对政治的忠诚的程度和意义。
C. 错误的假设女性的政治忠诚度对于政治无关紧要，正确
E. 低估了女性政治活动在女权运动中的角色，与“女权运动”无关，错误

错选了，重点应该是But these studies have focused on villages with limited land that are tied to a market economy rather than on the relatively isolated, self-sufficient communities with ample land characteristic of rain-forest regions. 对应d的one set和another set

之前有道题没有说转基因种子成本is likely to decline，是对比cost，把农药的cost和种子的cost对比，然后因为农民经常多用农药，所以weaken了农民因为“经济原因”选择转基因种子。
但这道题与cost无关
D. 直接给出转基因种子的一个缺点，weaken了likely to become the norm这个结论

There are two types of misdiagnoses the test could make:
1.) Diagnose appendicitis when the patient doesn't have it
2.) Diagnose nothing when the patient does have appendicitis.
In order to make sure they aren't missing any necessary surgeries, they need to eliminate #2.

重点在：without performing any fewer necessary ones than before，必要做手术的一个不会减少，不必要的是largely avoid
B. 错误的检测都是attributing appendicitis to someone who does not have it (把没得病的人检测成了得病需要手术的人)，所以不会误诊真正得了病需要手术的人

D. 以前大象没有吃过庄稼，吃过后发现他们prefer庄稼than野生植物，所以即使重修了庇护所，他们依旧会像以前一样
B选项这个事实在大规模工业化之前已经存在，题中最后的weird的解释一定是“大象吃庄稼”这个事实带来了什么样的后果，转折点在“大象吃庄稼”

答案错了吧

otherwise there would be more of them.

NP80%的居民要求扩建铁路以缓解高铁压力且愿意支付其费用。但这么做不能减少拥堵，因为____。
A. 同意扩建铁路的人认为高铁少拥堵是他们首要利益。（他们是使用高铁的人，有更多铁路也不会选择铁路，只是希望把其他人分去铁路，然而其他人也是这么想的话，扩建铁路就没得意义了~）
B/C. irrelative
D. irrelative(而且反正大家也愿意支付)
E. support了扩建铁路的proposal