D. it makes growth hard to continue

　　2. What can we infer from Paragraph 2?

　　A. China lacks wind and solar energy.

　　B. China is the leader of the low­carbon market.

　　C. High­speed trains are a low­carbon development.

　　D. Palm oil is made at the cost of valuable rainforest.

　　3. We can learn from the last paragraph that businesses have many chances to ________.

　　A. develop sustainable products

　　B. explore new natural resources

　　C. make full use of natural resources

　　D. deal with the major challenge

　　4. What is the main purpose of the passage?

　　A. To introduce a new business model.

　　B. To compare two business models.

　　C. To predict a change of the global market.

　　D. To advocate sustainable development.

　　B

　　More often than not, people will look at the phone screen to check for new messages or have a quick look at Facebook. Researchers have now found why we often feel such a strong need to look at our phones. Using the mobile phone, they say, is contagious (传染的).

　　A team says people are twice as likely to pull out their phones to check their text messages or e­mails if they're with someone that has just done the same. They also found that women were more likely to use their mobile phones than men. The team watched students in dining halls and coffee shops around the college, observing pairs of college students sitting at tables for as long as 20 minutes and recording their cellphone use. "What we found most interesting was just how often people were using their mobile phones，" Dr. Daniel Kruger, the study's co­author, said."Every person we studied used his or her phone at least once while one woman was on hers about half of the time. People saw others checking their incoming messages and began to check their own."

"Cellphones create another choice for one's attention and may both support and disagree with live social activities，" the researchers wrote. Kruger believed this could be explained by the effects of social inclusion (包含) and exclusion (排除). If one person in a pair starts a conversation through his phone, the other one may feel excluded and then feel the need to get in