April 11, 2003 12:44 a. m. PST, Associated Press   The respiratory(呼吸系统) virus known as SARS has appeared to spread in the United States only to family members of health workers with close contact to a sick person.
On Thursday, the head of the Centers for Disease Control and Prevention said there might be a case of severe acute respiratory syndrome（综合症） spreading through the workplace.
Dr. Julie Gerberding said a suspected SARS virus patient who became ill after traveling to Asia might have infected a co-worker in Florida, which made her “very worried”.
So far, a dozen people—nine family members and three health workers—were infected after coming into close contact with the person with SARS. The rest of the 166 suspected American cases have something to do with people who were infected while traveling in Asia.
In the Gainesville, Fla. area, a 47-year-old woman was believed to have been infected at work by a 60-year-old woman who was the nation’s first suspected SARS case, said Tom Belcuore, director of the Alachua County health department.
Since the World Health Organization announced a worldwide warning last month about SARS, the United States has started infection control in hospitals and among families of suspected cases.
Florida officials said a school in Okaloosa County went through a cleaning after a 6-year-old boy suspected of having SARS appeared at school with slight symptoms. “Health officials are watching the boys’ contacts at school to make sure no one else is infected,” said Rob Hayes, health department spokesman, “The boy may have been infected from a family member,” Hayes said, “We immediately became aware of it and had the child sent home. He’s staying at home with his family until 10 days after symptoms disappear.”
The researchers guessed that the virus might have come from animals. However, the scientists have not ruled out the possibility that some other microbe might also help make SARS more serious or easier to catch.
The best title for this text is _______.

A．A Worldwide Warning

B．Suspected SARS Cases

C．What Is SARS

D．Possible Spread of SARS in the USA

The writer wrote this text mainly to _______.

A．discuss the danger of SARS

B．report research result about SARS

C．inform people of the spread of SARS

D．explain to the readers what SARS is

How many cases of suspected SARS are there in the U.S.A. according to the text?
A. 166.             B.178.              C. 12.              D. 181.