In nineteen eighty-three, researchers discovered the human immunodeficiency virus as the cause of AIDS.
In nineteen eighty-three, researchers discovered the human immunodeficiency virus as the cause of AIDS.
1983年，研究人员找到了导致艾滋病的人类免疫缺陷病毒。
In nineteen eighty-three, researchers discovered the human immunodeficiency virus as the cause of AIDS.
1983年，研究人员找到了导致艾滋病的人类免疫缺陷病毒。