请教各位牛牛GWD1中的几个小题

moyuan

各位神仙辛苦拉!!

我是菜鸟一只,11.14去杀鸡.什么都不会.做个GWD VERBAL部分还错了23个.救救我啊~~~

13:In the United States, of the people who moved from one state to another when they retired, the percentage who retired to Florida has decreased by three percentage points over the past ten years. Since many local businesses in Florida cater to retirees, this decline is likely to have a noticeably negative economic effect on these businesses.
which of the following, if ture, most seriously weakens the argument?
A.Florida attracts more people who move from one state to another when they retire than does any other state.
B.The number of people who move out of Florida to accept employment in other states has increased over the past ten yrs
C.There are far more local business in Florida that cater to tourists than there are local businesses that cater to retirees
D.The total number of people who retired and moved to another state for their retirement has increased significantly over the past ten yrs
E.The number of people who left Florida when they retired to live in another state was greater last yr than it was ten yrs ago.

答案选D,我怎么觉得D是无关那.我的猜测是,答案中应有一种可能性:即使外来的retiree少了3%,本地的retiree多了很多,所以cater to retirees的business不会受太大冲击.可是D是怎么WEAKEN的呢??求助求助!!!(问题陆续补充中)

15.In parts of South America, vitamin-A deficiency is a serious health problem, especially among children. In one region, agriculturists are attempting to improve nutrition by encouraging farmers to plant a new variety of sweet potato called SPK004 that is rich in beta-carotene, which the body converts into vitamin A. The plan has good chances of success, since sweet potato is a staple of the region's diet and agriculture and the varieties currently grown contain lito beta-carotene.
which of the following, if ture, most strongly supports the prediction that the plan will succeed?
a.the growing conditions required by the varieties of sweet potato currently cultivated in the region are conditions in which SPK004 can flourish.
c.there are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.
b.d.e 就不看了明显错.

答案选A.我纳闷为什么A对.为什么C不对.该怎么破题呢?拿来这道题,我却一点思路都没有呢......

23.Past assessments of the Brazilian rain forest have used satellite images to tally deforested areas, where farmers and ranchers have clear-cut and burned all the trees, but such work has not addressed either logging, which is the removal of only selected trees, as well as surface fires, burning down individual trees but do not denude the forest.
B.which removes only selected trees, or surface fires that burn
D.removing only selected trees, or surface fires, burning