The claims that plastic bags are worse for the environment than paper bags or cotton reusable bags are dubious at best. In fact, compared to paper bags, plastic grocery bags produce fewer greenhouse gas emissions, require 70 percent less energy to make, generate 80 percent less waste, and utilize less than 4 percent of the amount of water needed to manufacture them. This makes sense because plastic bags are lighter andtake up less space than paper bags.
Reusable bags come with their own set of problems. They, too, have a larger carbon footprint than plastic bags. Even more disconcerting are the findings of several studies that plastic bag bans lead to increased health problems due to food contamination from bacteria that remain in the reusable bags. A November 2012 statistical analysis by University of Pennsylvania law professor Jonathan Klick and George Mason University law professor and economist Joshua D. Wright found that San Francisco's plastic bag ban in 2007 resulted in a subsequent spike in hospital emergency room visits due to E. coli, salmonella, and campylobacter-related intestinal infectious diseases. The authors conclude that the ban even accounts for several additional deaths in the city each year from such infections.（官方指南p204）
All of this decline was playing out at a time when the U.S. was embroiled in two overseas wars, with hundreds of thousands of Americans deployed in Iraq and Afghanistan. It was happening as domestic politics grappled with the merits and consequences of a global war on terror, as a Great Recession was blamed in part on global imbalances in savings, and as world leaders debated a global trade treaty and pacts aimed at addressing climate change. It unfolded as American workers heard increasingly that their wages and job security were under assault by competition from counterparts on the other side of oceans.
In short, news of the world is becoming palpably more relevant to the day-to-day experiences of American readers, and it is rapidly disappearing. （官方指南p184）
美国三月真题的作文部分（A Call for National Service）前三段也是如此安排，这种写作手法并不罕见。因此，考生须切记议论文从来不是论点与论据的简单堆砌，作者会用相应的论证将其联系起来，如果本段内没有，那么大多是在下文。
一个常识是，只要作者在文中使用了转折，那么论述重点在于转折之后的部分。所以在新sat文章中，见到but, yet, however等转折词时要明确其后的内容才是作者的表达重心。如：
We all know the power of Twitter, Facebook and other forms of social media to connect readers in one place with images and impressions from situations unfolding far away. We know the force of social media during the Arab Spring, as activists convened and reacted to changing circumstances. . . . Facts and insights reside on social media, waiting to be harvested by the digitally literate contemporary correspondent.
And yet those of us who have been engaged in foreign reporting for many years will confess to unease over many of the developments unfolding online, even as we recognize the trends are as unstoppable as globalization or the weather. Too often it seems as if professional foreign correspondents, the people paid to use their expertise while serving as informational filters, are being replaced by citizen journalists who function largely as funnels, pouring insight along with speculation, propaganda and other white noise into the mix.（官方指南p184）