解不等式
相当于 X*(2X - 9) ≤ 0 且 X ≠ 0
0 ＜ X ≤ 9/2

设题目所求为X
X/4.5 + (500 - X)/3.5 = 120

(4.5+0.5)X+(6+1)*(Y-X)

还是不懂。就算是根据过去几年平均量之类的设置的quota，那已经预期到将会有quota限制，文中没有说到底几年后会有quota，万一就是明年限制呢？那今年增加了耕种岂不是就惨了。如果等个三五年再限制，那这三五年倒是可以增加耕种。所以不知道未来哪年限制的情况下，怎么可以判断增加耕种可以？

有个傻缺 在每道题里都说自己做对了

D：列等式：因为飞机总费用占一半，所以飞机总费用=其他交通工具总费用
而总费用=平均费用*人数，有题可知，其他交通工具总人数>飞机总人数
所以：飞机平均费用>其他交通工具平均费用

mark解释！！
不是因果，而是枚举推理（百分比陷阱）。前提中的“45 percent”是重要信息点。
OG对D的解释：This suggests that even if the proportion of Canatrians eating at fast-food restaurants declines, the total number doing so may not decline. Thus, the total demand for and profitability of fast-food restaurants may not decline either, so the total number of fast-food restaurants in Canatria may not decrease.
显然，“proportion”和“total number”也证明了推理模式为枚举推理（百分比陷阱）。

1、本身有专门的名词形式的比动名词更好。2、you can't use 'resulting from' as an adverbial modifier, as is done here. in general, 'resulting from' is only used as an adjective modifier, almost always without a comma, as in
the pollution resulting from the chemical spill forced all the local residents to evacuate.（by Ron）

楼下key takeaway
aim at doing，因为aim本身就含有目的的意思，aim to do就显得累赘。同理the goal of doing 而不是the goal to do

A: not A or B (not A nor B是错误的); about 前加了逗号指preoccupied about & curious about 错误 (应该是preoccupied with)
E: it指reasons错误

D: could also say "unforeseeable weather"就不要wordy的说weather that is unforseeable

B: 没有并列关系
C: trying (to do sth) may be worthwhile 试图这件动作不是worthwhile的
D: sth may be worthwhile to try (to do 多余）

楼下key takeaway
A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

as 意思是 because; 意思换了
flat 和 flatly都有副词的词性，flat表示平直地，flatly表示断然地
and so 可以连用

the earthquake (A event）is like eruption (B event); the effect is not like the eruption

错误的搭配：
more ... as ... / as ... than ... / more ... compared with
more... rather than / rather... more than

A中的been应该改为done

when conversing with another blind person是与when speaking平行的结构

because of身后的enhancing reproduction or survival是动名词短语，而动名词是没有“逻辑主语”的。但在本题中，被favor的必须是the products of natural selection，即，are favored在本题中必须有逻辑主语，否则无法满足语境中给出的逻辑关系。

题意理解错误