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：形容词辨析题。空格所在句的句首用But开头，表示转折，说明此句是对前一句“随着天气变暖，新病例似乎逐渐减少”的否定。也就是说，疫情并没有减缓，反而是更严重了。根据空格所在句语意，几乎每个州都有 流感病情。此处应填入一个形容流感更为严重的形容词，用于和前一句形成转折。故本空应填入significant，表示“显著的流感病情”，以强调它的严重性。

错项排除：A项excessive用于表示强调“过度，过分”的意思，不符合原文逻辑，故排除。B项enormous用于表示强调数量、体积或尺寸等的庞大，无法用于形容疫情的严重性，故排除B。D项magnificent强调整体的事物是壮观的，不能用于形容事物数量的多少，故排除D。