请教，并请各位指正语法做题思路

下面这些就是我做GWD-24中的SC的思路，刚刚做的，我觉得分析的时候自己思路清晰了一些。也许是因为时间比较充裕，可以多思考一些。
 1
Tom Bradley was mayor of Los Angeles from 1973 to 1993, an era when the city had transformed from a collection of suburban neighborhoods to the second-largest city in the United States                       （E）
an era when the city had transformed.
an era during which the city was transformed.
an era that transformed it.
during which era the city transformed.
during which the city was transformed.
我的思路：由意思可以得知，引导的是一个时间状语从句，这个时间是时间段，用during which更加准确，排除a,c；城市是被动的变化，排除d；在B，E中比较，觉得E更舒服一些。所以就选了
 
 

2，According to public health officials, in 1998 Massachusetts became the first state in which more babies were born to women over the age of thirty than under it. （A）
A.     than  
B.     than born  
C.     than they were 
D.     than there had been 
E.      than had been born.
思路：我认为是主语之间的比较，意思是超过30岁年龄所生的婴儿比30岁以下的多，是婴儿人数之间的比较。这句话补全为more babies were born to women over the age of thirty than  babies were born to women under it. 
8
The results of the company's cost- cutting measures are evident in its profits, which increased five percent during the first three months of this year after it fell over the last two years.          （C）     
which increased five percent during the first three months of this year after it fell
which had increased five percent during the first three months of this year after it had fallen
which have increased five percent during the first three months of this year after falling
with a five percent increase during the first three months of this year after falling
with a five percent increase during the first three months of this year after having fallen
思路：寻找increase和 fall的逻辑主语，发现是profits，只有利润可以上升和下降，而results不能用这样的此形容，排除D，E；排除A，B，时态错误，要与主句的大时态保持一致，强调的也是对现在的影响，所以要用现在完成时。
 
9
Part of the proposed increase in state education spending is due to higher enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at a record high.   (D)
enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at.
enrollment, with a number of students in public schools growing steadily since the mid-1980's and, at nearly 47 million, reaching.
enrollment: since students in public schools have grown steadily in number since the mid-1980's and, at nearly 47 million, have reached.
enrollment: the number of students in public schools has grown steadily since the mid-1980's and, at nearly 47 million, has reached.
enrollment: students in public schools have grown steadily in number since the mid-1980's and , at nearly 47million, are at
思路：首先用数排除A，the number of 的用法；since+时间，要用完成时，排除B；是学生的人数达到了一个 record high，而不是学生，排除C，E。
 
17
The yield of natural gas from Norway's Troll gas field is expected to increase annually until the year 2005 and then to stabilize at six billion cubic feet a day , which will allow such an extraction rate at least for 50 years' production        （B）
A.     2005 and then to stabilize at six billion cubic feet a day, which
will allow such an extraction rate at least for
B.     2005 and then to stabilize at six billion cubic feet a day, an
extraction rate that will allow at least
C.     2005 and then stabilizing at six billion cubic feet a day, with
such an extraction rate at the least allowing
D.     2005, then stabilizing at six billion cubic feet a day, allowing
such an extraction rate for at least
E.      2005, then stabilizing at six billion cubic feet a day, which will
allow such an extraction rate for at least
思路：C，D，E中的stabilizing的逻辑主语为 the yield，这样的搭配读下来觉得没有expected to stabilize 的表达恰当，排除C，D，E；A中which指代不明，它可以指代and的前半句，也可以指代后半句，从意思上讲它是指代后半句的，排除。B中用一个名词复述前面的指代内容，然后用定语从句修饰完善，没有歧异和错误。
 
Q 19:
In archaeology, there must be a balance between explanation
of the value and workings of archaeology, revealing the mys-
teries of past and present cultures, and to promote respect for
archaeological sites.   （E）
 
A.     between explanation of the value and workings of archae-
ology, revealing the mysteries of past and present cultures,
and to promote
B.     among explaining the value and workings of archaeology,
revealing the mysteries of past and present cultures,
and promoting
C.     between explaining the value and workings of archaeology,
revealing the mysteries of past and present cultures,
and when promoting
D.     among explaining the value and workings of archaeology, the
revelation of the mysteries of past and present cultures,
and to promote
E.      between explaining archaeology's value and workings, in the
revealing the mysteries of past and present cultures,
and in promoting
思路：我知道这个考的平行结构，但是觉得很混乱 。balance是两者之间的平衡关系，所以排除B，D；我把E理解为在explaining and working中平衡，在revealing..., and 在promoting...方面。

 

其中19（B）

1(B)这两道题做错了，我参考了一些关于这个的链接

请各位帮我看看我的做题思路，恳请提出宝贵意见和见解！

相信一些XDJM也很需要这种帮助！

自从考GMAT失利后，我就在反思。

在新东方上辅导班的时候，我特别认真记忆语法老师所讲的东西，当时我也坚信只要这样坚持下来我在语法方面就没有问题了。

但是情况很糟糕，做了PP才知道自己的语法问题很大。做语法题，最怕的就是面前有一道题，但是你却对它没有一点感觉，不知从何下手！所以，我做一道题错一道题，自己当时也相当的沮丧。最后硬着头皮去考，可想而知，结果有多么的不理想。

痛定思痛，我认为自己在解题思路上是有问题的，所以我先从这方面入手吧。

希望各位能够指点！

谢谢！