economics and one of Benjamin Franklin's most memorable sayings:"Time is money. " To those at the forefront of modem time-banking, that is the appeal.

28. What's the main purpose of the Silver Spring Time Bank?

A. To better serve the local economy.

B. To help people get to know more friends.

C. To provide the elderly with timely financial help.

D. To build community by exchanging time credits for services.

29. How did the Liepolds pay for their ride?

A. In cash. B. By credit card.

C. By cheque. D. With time credits.

30. What does the underlined word "that" in the last paragraph refer to?

A. Making friends. B. Classical economics.

C. Modem time-banking. D. Franklin's famous saying.

31. What is the suitable title for the text?

A. Time is money B. The more friends, the better

C. Giving the gift of time D. Swapping time credits for services

28---31．DDA D

　　　　　　　　　　　　　　　　　　D

How often have you read a story that a friend or family member has sent you？Very likely you would have skipped the news had it not been pointed out to you.

Traditionally newspapers and famous TV channels have been our source of authentic news. But these days with the popularity of social media，sharing stories is increasingly becoming a favorite source of news. In fact，research suggests that more than half the people get their news today from social media such as Facebook，Twitter and Google.

Social media sites often aggregate contents for us to see based on trending topics-stories that have been viewed by many others as well as based on our own past searches and analysis of our likes and dislikes. If you have liked kittens in the past，you may have noticed that you are seeing more news，blogs and analysis about kittens all of a sudden.

While advocates of free speech do not want to control any voice，it is certainly harmful when it is difficult to separate truth from fiction. Imagine the influence of fake(虚假的) news when it begins to affect our own lives. Trusting a piece of news，patients could very easily fall for wrong diagnosis; elders could give money to cheats and reputation of perfectly upright citizens could be easily ruined. What about when we research for a school project and base our analysis on false information or news?

Mark Zukerberg has finally acknowledged the issue. Among several projects that the company is considering，Facebook is trying to take powerful measures to crack down on false news. This would include warning labels on fake contents. Fake news also makes a lot of profits from advertising. Google and Facebook have said they will limit advertising profits on their network from such sites.