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。空格所在句的大意为，疫情的严重程度是温和的，绝大多数患者只出现了轻微症状，而且通常在 经过任何医疗治疗的情况下可以完全康复。根据语意可知，此处应表示没有经过任何治疗就可以痊愈，而且由空格后的any可推断，空格处应填入一个具有否定含义的词。故本空应填入absence。

错项排除：A、D两项代入空中和in搭配应该构成in progress（进行中）和in favor of（支持，赞成），不应有the，且代入空中和语意不相符，故排除A、D两项。C项presence表示“有，存在”，与absence是反义词，和原文意思相悖，故排除C项。

长难句分析：But the epidemic is “moderate” in severity, according to Margaret Chan, the organization’s director general, with the overwhelming majority of patients experiencing only mild symptoms and a full recovery, often in the absence of any medical treatment.

本句主干为But the epidemic is “moderate”…，为主系表结构。后面的according to Margaret Chan为插入语，用于说明前一句内容的来源，the organization’s director general是Margaret Chan的同位语，用于对Margaret Chan的身份进行解释说明。随后的with引导独立主格结构，作主句的伴随状语，用于说明“流感病情是温和的”。句末的in the absence of…作状语修饰experiencing…a full recovery。

句意为：但据世界卫生组织总干事陈冯富珍说，疫情的严重程度是“温和的”，绝大多数患者只出现了轻微症状，而且通常在没有任何医疗治疗的情况下可以完全康复。