By the end of the year, a 3D-printed bridge will be put to use in China for the first time.

Different     1     traditional bridges, its     2     (create) design doesn’t use reinforced concrete. It is made of a new material     3     (design) to weather rain and sun for     4     extended period, and that’s durable enough to meet national construction industry standards. If parts of the bridge become damaged, they can be   repaired     5     (separate).

The 15-meter-long footbridge in Shanghai,     6     will have service life of up to 30 years, will take 35 days to build, according to     7     (it) chief architect. The complex curved surfaces of the bridge can only be achieved by     8     (use) 3D printing technology. Based on laboratory testing, it can bear a load of 250 kilograms per square meter.

This isn’t the first time that a 3D-printed bridge     9     (make) in China. In July last year, Tongji University in Shanghai made the world’s first two 3D-printed pedestrian bridges.

    10    , that pair of bridges was only built as a demonstration, and not for actual use.

Increasingly, Americans are becoming their own doctors by going to diagnose their symptoms, order home health tests or medical devices, or even self-treat their illnesses with drugs from Internet pharmacies(药店).Some avoid doctors because of the high cost of medical care, especially    1     they lack health insurance. Or they may stay away because they find it    2    (embarrass) to discuss their weight, smoking, alcohol consumption or couch potato habits. Patients may also fear what they might learn about their health, or they distrust physicians because of negative     3     (experience) in the past. But    4    (play) doctor can also be a deadly game.

Every day, more than six million Americans turn to the Internet    5    medical answers--- and most of them aren’t nearly sceptical enough of what they find. A 2002 survey by the Pew Internet &American Life Project found that 72 percent of those    6    (survey) believe all or most of what they read on health websites. They shouldn’t look up “headache” and the chances of finding     7    (rely) and complete information, free from a motivation for commercial gain,    8     (be) only one in ten, reports an April 2005 Brown Medical School study. Of the 169 websites the researchers rated, only 16 scored as “high quality”. Recent studies found faulty facts about all sorts of other disorders, causing one research team to warn that a large amount of incomplete, inaccurate and even dangerous    9     (inform) exists on the Internet.

The problem is most people don’t know the safe way to surf the Web. “They use a search engine like Google, get 18 trillion choices and start clicking. But that’s risky, because almost anybody can put up a site that looks authoritative ( 权威的)，so it’s hard to know if what you’re reading is     10    (reason) or not,” says Dr.Sarah Bass from the National Cancer Institute.