题目内容：
Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter.Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.Questions are based on the following passage.
Two groups of scientists demonstrated last week for the first time that the body launches a massive, effective counter-attack on the virus soon after infection of HIV begins. If doctors can figure out how to reproduce that early, powerful immune response, they might be able to develop better treatments to 1 stages of the disease. The researchers should be _2_ and more than a bit of luck. After all, to study someone at the beginning of a relatively 3 phase of the HIV infection, they had to find people who did not yet realize they had contracted the virus. It 4 that at least a third of HIV-infected people develop a fever or a severe sore throat within a few weeks to months after first 5 . Such signs, which usually clear up in their own, can easily be 6 as a bad flu. In order to identify seven young men suffering from a primary HIV infection, the researchers took this project by 7 . in hospital emergency rooms and talking to colleagues.
Using advanced laboratory tests that had been developed only in the past few years, both sets of scientists discovered an 8 growth of virus in the men's blood streams. Each liter of the men's blood contained as many as 10 million infectious viruses.
Within days after the virus burst, the researchers measured a rapid increase in the bloodstream of the number of anti-HIV antibodies (抗体). These Y-shaped bits of protein sought out the virus and targeted it for 9 . Once the antibody attack reached full scale in the seven test subjects,' the level of HIV in the bloodstream dropped 10 . In the majority of cases, the researchers could detect little or no virus two to three weeks later. In other words, the normal immune system can shut down the AIDS virus. Now researchers must figure out exactly how the body puts together this early effective defense and how the virus manages, years later, to avoid it.
A．destruction F．exemplified K． testifies
B．interrupt G．persistent L．lively
C．impair H．exposure M．explosive
D．residing I．abruptly N．silent
E．misdlagnosed J．segregation O．exhausting
选：__________
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