【正确答案】 1、microbicides and ARVs    

【答案解析】[解析]本题应锁定文章第六段。该段最后两句提到：At best，microbicides may be 80%effective in preventing the transmission of the virus during intercourse．To improve the chances that the virus doesn't slip by，however，there is always the possibility of combining the ARVs…。由此可知，防止HIV病毒传播的最有效方式是将microbicides和ARVs结合使用，故本题应填入microbicides and ARVs。