硅酮隆胸植入物a silicone breast implant一种叫作吡啶酮的新型抗艾滋病药物能促使艾滋病毒变异，使其不能繁殖，也不会再感染新的细胞。A newer anti-HIV drug called pyridinone caused HIV to mutate into a form which could not reproduce or infect new cells.所有的主要难点都涌现在烯酮 ( 1 ) 的合成中....
锋利的刀刃可能会划伤皮肤，导致出血。A sharp blade is likely to nick the skin and draw blood.用一把非常锋利的刀将褐色的皮从肉上剥去。Pare the brown skin from the meat with a very sharp knife.地上铺满了棱角锋利的石子。The ground was strewn with sharp-edged pebbles....