专四听写训练121：First Sign of AIDS
The virus causing AIDS enters the blood and quickly penetrates certain white cells in the body. / At first there is often little or no trace of the virus at all. / This situation usually lasts for six to twelve weeks. / During this time the person is free of symptoms / and antibody tests are negative. / The first thing that happens after infection / is that many people develop a flu-like illness. / This may be severe enough to look like glandular fever / with swollen glands in the neck and armpits, / tiredness, fever and night sweats. / Some of those white cells are dying, / virus is being released, / and for the first time the body is working hard to make correct antibodies. / At this stage the blood test will usually become positive. / Most people do not realize what is happening, / although when they later develop AIDS they look back and remember it clearly. / Most people have produced antibodies in about twelve weeks.