代入法

总共是4*3*2*1=24中排列方法
因为4株花都是不一样的， 刚好红花在里面有2中，白花在两端也有2种， （2+2）/24=1/6

If he is to ride 3 times and since he can choose any of the 3 cars each time, total number of ways is
= 3 * 3 * 3
= 27

Now the number of ways if he is to choose a different car each time is
= 3 * 2 * 1
= 6

So the probability is
= 6/27
= 2/9

(1) M>500
(2) J = 2M-400
(1)－(2) J-M= M-400>100
=> 注意不需要完全带入 要了解列式的目的

an integer in base 10 notation 十进制整数

d选项的having been based on is wordy, 并且it is unclear whether it modifies research conducted by the automobile company or the research conducted by the insurance company.

错选A）没有表达出和land value的关系
B）high land value-> multistory buildings

as there is in Britain比unlike Britain把英国有的意思表达得更明确；comma+unlike sth最好是放在句首，跟主句主语比较；unlike除了做介词，+名词，也可以做连词，B改成unlike in Britain会更好

用毕老师等话术来讲，no linguistic这个fact对estimate起的约束强，因此to do不定式更加。

differentiate A from B,
differentiate between A and B;
distinguish A from B,
distinguish between A and B, 区分；
distinguish sth，识别某物

to be an even more serious deterrent to the nuclear industry than political opposition会引起歧义：是一个更大的威胁，比起是一个政治反对。is保留更佳。
要用is，前面就得有sth be这个结构，只剩D了

(A) were no Jane Austens or Brontë sisters ("were" works with both items because they're both plural)
(C) was not Jane Austen nor the Brontë sisters (singular "was" doesn't work with plural "sisters")
We can eliminate options C, D, & E because they use a singular verb with the plural Brontë sisters.
There were no Xs or Ys = CORRECT
There were not Xs or Ys = INCORRECT

by the Center for Media and Public Affairs是修饰study，读出这个关系后，后面study的同位语修饰可以和这个修饰放在一起修饰study，
再对Center进行同位语修饰。

其他选项有修饰对象混淆以及代词指代不明等错误。

A：看起来像graders浪费了rainwater
C：there is no rainwater wasted
E：前后是有目的关系，并非并列。

A选项：复数代词they在语法上只能指代复数名词wasps，但是在逻辑上，由女王和工人组成的应该是某一个社会（society）而不是wasps。

倒装

C选项：especially if it has worked well in the past是条件状语。状语和定语均属于修饰成分，均具有就近修饰的原则。本选项中距离这个条件状语最近的句子是when they do appear。但是，在逻辑上，该条件状语应该是be committed to的修饰语。

选项C中第二个代词it的指代对象只能是单数名词，但其逻辑上应该指代复数名词languages。

B Correct. Th e costs to maintain the roads are
emphasized in this sentence construction;
dirt roads cost and paved roads do (cost
understood) are parallel.

定位： Moreover, chance events—which may indicate nothing about the direction of trends in population size—may lead to its extinction.

定位到这一句：Although limiting information collection could increase the risk that researchers will overlook facts relevant to a study,