GWD-5-Q15:

Lightbox, Inc., owns almost all of the movie theaters in Washington
                County and has announced plans to double the number of movie screens it has in the county within five years.  Yet attendance at Lightbox’s theaters is only just large enough for profitability now and the county’s population is not expected to increase over the next ten years.  Clearly, therefore, if there is indeed no increase in population, Lightbox’s new screens are unlikely to prove profitable.

Which of the following, if true about Washington
                County, most seriously weakens the argument?

1.  

2.  

3. In selecting the mix of movies shown at its theaters, Lightbox’s policy is to avoid those that appeal to only a small segment of the moviegoing population.　新东方老师说，要说明这个政策的变化才行，在之前之后都起作用变化前后一样是无法削弱的——这个解释是什么意思？

4.  

5. There are no population centers in the county that are not already served by at least one of the movie theaters that Lightbox owns and operates.　
                   E去了no是什么意思？这个城市的人口中心的人没有看过至少一部Light的电影？

我看不出C和double the number of movie screens有什么关系.无论是否double the number of movie screens,C都能起到作用.我想这就是“在之前之后都起作用变化前后一样是无法削弱的”；

E是说Lightbox拥有的戏院覆盖了整个county，也就是说，county里没有lightbox覆盖不到的地方。说实话，我看不出E和题目有什么直接的逻辑关系。new screens profitable与否取决于new screens能否增加观众数目，E答案和这个条件没有关系。