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：动词短语辨析题。根据空格所在句语意，在恐慌最严重的时候，墨西哥城的大部分地区都关闭了，纽约市、美国西南部以及全世界的病例开始 。可见此处是在描述流感病例不断出现的情况，故本空应填入crop up，用于强调病例是在其他地方突然出现的。

错项排除：A、D两项代入空中，明显不符合语义，病例和“熬夜”或者“掩盖”没有任何关系。A项中的stay up也可表示“待在原地不动”，但由前文可知，流感是在墨西哥城爆发，随后又说在纽约等地“停留”，语义上逻辑不通，应该是在纽约等地“新出现”，故A、D两项错误。根据语意，流感是逐步蔓延到其他地区的，而不是一开始就“充满了”其他地区，C项与文意不符，故排除。