diseases like diabetes (糖尿病) and heart disease .

　　Unfortunately when people become industrialized . if they adopt this Western diet , they are going to have these health problems , especially in developing countries in Asia .China is an example where the number of diabetes cases has been jumping from less than one percent to 10 percent of the population as they began to industrialize over a 20-year period . And that is happening all across the world , in Mexico , in Nigeria and so on .

　　And , a diet bad for human beings is also bad for the environment . As the world's population grows , more forests and tropical(热带的)areas will become farmland for crops or grasslands for cattle . We are likely to have more greenhouse gas in the future from agriculture than that coming out of all forms of transportation right now .

　　Mr. Tillman calls the link between diet , the environment and human health , "a trilemma" - a problem offering a difficult choice . He says one possible settlement is leaving the Western diet behind .

　　29 . According to the passage , more greenhouse gas might be given off in the future from .

　　A . transportation B . developing countries

　　C . agriculture D . developed countries

　　30 . What does David Tillman believe ?

　　A . Diet , the environment and human health are closely connected .

　　B . The Western diet is the only choice as the nation industrializes .

　　C . People in tropical areas are more likely to have heart disease .

　　D . The traditional diet is more balanced than the Western diet .

　　31 . What can we infer from the passage ?

　　A . Nigeria has the largest number of diabetes cases .

　　B . Overweight people are at higher risk of infectious diseases .

　　C . The examined information comes from developing countries .

　　D . Industrialization contributes to the spread of the Western diet .

　　D

　　Americans , especially the millennials (千禧一代), are always glued to their phones. A common day of an average university student in American starts off like this : an alarm clock wakes you up , which is quickly followed by checking social media such as Twitter and Facebook . Once in classes , you are again attracted by your buzzing phone and access to the Internet rather than pay attention to the lecturing professor . Then you have lunch with some friends , only to look up from your screen to realize that no one has said a word in five minutes and instead all are looking at their phones . Once the day ends , you can't help checking all forms of social media again before finally being able to shut your eyes only to repeat this vicious cycle the next day .

　　Cyberbullying(网络霸凌),a concept unknown before , is now in fashion . Many of the millennials are using the Internet to make jokes about others to extremes . The Internet gives cowards bravery . People feel like their actions and words have no bad results because they cannot see the pain they cause others .

　　Millennials also tend to think that whatever information shows up on their screens must be taken as truth, whether the source is reliable(可靠的) or not.

Social media is not all bad , however . People are still able to use social media to connect with friends and family who live a great distance away . With a few clicks , someone could make another