The outbreak of swine flu that was first detected in Mexico was declared a global epidemic on June 11, 2009. It is the first worldwide epidemic (1) _____ by the World Health Organization in 41 years.

    The heightened alert (2) _____ an emergency meeting with flu experts in Geneva that assembled after a sharp rise in cases in Australia, and rising (3) _____ in Britain, Japan, Chile and elsewhere.

    But the epidemic is “ (4) _____ ” in severity, according to Margaret Chan, the organization’s director general, (5) _____ the overwhelming majority of patients experiencing only mild symptoms and a full recovery, often in the (6) _____ of any medical treatment.

    The outbreak came to global (7) _____ in late April 2009, when Mexican authorities noted an unusually large number of hospitalizations and deaths (8) _____ healthy adults. As much of Mexico City shut down at the height of a panic, cases began to (9) _____ in New York City, the southwestern United States and around the world.

    In the United States, new cases seemed to fade (10) _____ warmer weather arrived. But in late September 2009, officials reported there was (11) _____ flu activity in almost every state and that virtually all the (12) _____ tested are the new swine flu, also known as (A) H1N1, not seasonal flu. In the U. S., it has (13) _____ more than one million people, and caused more than 600 deaths and more than 6,000 hospitalizations.

    Federal health officials (14) _____ Tamiflu for children from the national stockpile and began (15 ) _____orders from the states for the new swine flu vaccine. The new vaccine, which is different from the annual flu vaccine, is (16) _____ ahead of expectations. More than three million doses were to be made available in early October 2009, though most of those (17) _____ doses were of the FluMist nasal spray type, which is not (18) _____ for pregnant women, people over 50 or those with breathing difficulties, heart disease or several other (19) _____. But it was still possible to vaccinate people in other high-risk groups: health care workers, people (20) _____ infants and healthy young people.

答案精析：名词辨析题。空格前的rising和前文的a sharp rise都表示“增加”的意思，由and可知，前后应为并列关系。因此，and前后的内容表达意思相近。and前说到澳大利亚病例的激增，故空格处应填入一个和“病例”含义相同的词，numbers代入空中表示“病例数的增加”，故本空应填入numbers。

错项排除：A项digits表示“数字，数位”，并不能表示“数量”，所以不能和前面的rising搭配，故排除A项。C项amounts虽可以表示“数量”，但其修饰不可数名词，而原文中的cases为可数名词，故C项错误。D项sums表示“总数，总和”，代入空中不能表达“病例数”，故排除D项。

长难句分析：The heightened alert followed an emergency meeting with flu experts in Geneva that assembled after a sharp rise in cases in Australia, and rising numbers in Britain, Japan, Chile and elsewhere.

本句主干为：The heightened alert followed an emergency meeting…，为主谓宾结构。emergency meeting后面有两个介词短语with flu experts，in Geneva作后置定语，修饰emergency meeting。后面that引导定语从句修饰flu experts，用于解释流感专家聚集开会的原因。

句意为：随着澳大利亚病例数量急剧上升，以及英国，日本，智利和其他地区感染人数的不断增加，日内瓦的流感专家召开了紧急会议，会议后加强了对流感的警觉性。