[填空题]It (know)（）to all that the World Trade Center in New York is the highest building in the city.

[填空题]It (know)（　）to all that the World Trade Center in New York is the highest building in the city.

[填空题]It (know)______to all that the World Trade Center in New York is the highest building in the city.

[填空题]Many workers who worked in the World Trade Center after the September eleventh attacks became sick. They breathed a mix of dust, smoke and chemicals in the ruins of the Twin Towers and a third building that fell. Some went clays without good protection for their (36) . Five years later, many of the thousands who worked at Ground Zero in the early days after the attacks still have health problems.
Doctors at Mount Sinai Medical Center in New York City have (37) the results of the largest study of these workers. The study (38) high rates of breathing problems in members of the building traders, firefighters, police officers and other workers. Almost seventy percent of the workers in the study had a new or worsened breathing problem. These problems developed during or after their time working in the mountain of (39) . About sixty percent still had breathing problems at the time of their (40) . The researchers say they decided to s

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What does the World Trade Center look like now

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We still do not know all of the reasons why babies are born sick or with major disabilities. But we do know (31) . One baby, maybe more, (32) of one hundred is born with a serious genetic problem. Gene therapy (33) a very real possibility of correcting many of these disorders. It could transform — indeed, it already has — lives that are doomed (34) the pain and anguish of chronic illness. But scientific advances can also generate misunderstanding and fear. The Salk polio vaccine, so closely identified (35) the March of Dimes, was one of the most important medical gains of our time. It was safe. It worked. But (36) earlier vaccine used "live" viruses that caused fatalities, researchers (37) to overcome public apprehension.
Some critics are concerned that gene therapy will be abused create "super" humans. (38) are disturbed about possible disclosures of personally sensitiv