???? ??????? ??? ????? ?? ??? ??? ???? ? ?? ???? ??? ?????.Manufacture and sale of sildenafil citrate medications is popular in China, exactly where copyright's patent claim isn't widely enforced.?? "??? ?? ?? ??? ??? ???? ???? ????"? ??? "???? ???? ????? ??? ?? ? ??. ?? ?? ??? ????? ??? ??? ???? ????"? ???.?????? ????? ??? ??? ??? ??? ???? ??? ???