sentence1: The Czech Republic has allowed at least 94 prisoners over the past decade to be surgically castrated. It is the only country in Europe that uses the procedure for sex offenders. Czech psychiatrists supervising the treatment - a one-hour operation that involves removal of the tissue that produces testosterone - insist that it is the most foolproof way to tame sexual urges in dangerous predators suffering from extreme sexual disorders. Surgical castration has been a means of social control for centuries. In ancient China, eunuchs were trusted to serve the imperial family inside the palace grounds; in Italy several centuries ago, youthful male choir members were castrated to preserve their high singing voices.
sentence2: In China sex offenders have to be treated with surgical castration.