Bush also contended that it would be difficult to enforce a ban on reproductive cloning while allowing research cloning, and he called the presumed benefits of research cloning "highly speculative."

布什并且坚信，很难在禁止复制性克隆的同时允许研究性的克隆，他说对研究性克隆好处的推测是“高度投机的”。

Strictly enforce the ban on reactionary secret societies.

认真贯彻取缔会道门.

And directed Commissioner Lin Zexu to enforce the ban.

并指派林则徐作为禁烟专员

The European Union began to enforce a ban five years ago.

欧盟五年前就已经开始执行禁令。