根据下列文字，回答题。Scientists around the world are racing to learn how to rapidly diagnose, treat and stop the spread of a new, deadly disease. SARS--Severe Acute Respiratory Syndrome--was (31) __________for the first time in February 2003 in Hanoi, (32) __________ since then has infected more than 1,600 people in 15 countries, killing 63. At this (33) __________ , there are more questions than answers surrounding the disease.
Symptoms start (34) __ a fever over 100.4 degrees F, chills, headache or body (35) within a week, the patient has a dry cough, which might (36) __ to shortness of breath. In 10% to 20% of cases, patients require (37) __________ ventilation to breathe. About 3.5% die from the disease Symptoms (38) __ begin in two to seven days, but some reports suggest it (39)__________ take as long as 10 days. Scientists are close to (40) __________ a lab test to diagnose SARS. In the meantime, it is diagnosed by its symptoms. There is no evidence (41)__________ antibiotics, or anti-viral medicines help, (42) __________ doctors can offer only supportive care. Patients with SARS are kept in isolation to reduce the risk of (43)
Scientists aren't sure yet, but some researchers think it's a (44) __________discovered coronavirus, the family of viruses that cause some common colds.
Most cases appear to have been passed (45) __droplets expelled when infected patients cough or sneeze. Family members of infected people and medical workers who care (46) __ them have been most likely to (47) __________ the illness. But recent developments in Hong Kong suggest that the (48) __ might spread through air, or that the virus might (49) ___________ for two to three hours on doorknobs or other (50) ___________. Health experts say it is unlikely, though, that sharing an elevator briefly with an infected person would be enough to pass the rims.回答第31空。