我觉得FEIFEI里的解释还可以啊，如下：请注意大号字 In my view, the reasoning in this argument is that: More than a third of children in the United States watch television for more than five hours a day; in South Korea the figure is only 7 percent. But whereas less than 15 percent of children in the United States understand advanced measurement and geometric concepts, 40 percent of South Korean children are competent in these areasà The more television children watch, the less competent they are in mathematical knowledge
Under this circumstance, it is obvious that the arguer establish the casual relationship between the television children watch and the competent they are in mathematical knowledge. We can anticipate the correct answer of assumption from two directions. For one thing, the answer should assure the casual relationship between the television children watch and the competent they are in mathematical knowledge. For another, the answer should rule out other possibility that may lead to the more competent the children in South Korea are in mathematical knowledge.
After this anticipation, we can find that E is the sound chose. Because E rules out other possibility that may result in the more competent the children in South Korea are in mathematical knowledge.
A is out of scope. We cannot assure the casual relationship between the interest of children and the competent they are in mathematical knowledge. B is out of scope too. The reasoning that the fact that South Korean children are more disciplined about doing schoolwork can result in the more competent the children in South Korea are in mathematical knowledge is open to doubt. C is puzzle. At first glance, C may be the correct answer. But after a careful examination, we will find that C is incorrect. We cannot ensure the casual relationship between the televisions the children watch and the competent they are in mathematical knowledge either. Such as, the students who want to crack GMAT will play less basketball. But we cannot guarantee the casual relationship between the ability of the students cracking GMAT and the activity of playing basketball. D is out of scope. It is possible that more children in South Korea who watch television less than five hours but more than one hour a day than the children in US. If so , D has no effect on this argument. | 
