奥巴马：戒烟

With all the challenges President Barack Obama has faced, quitting smoking might be one of the hardest. Obama, 50, used to light up about five times a day, but is now tobacco-free, according to a recent medical exam.

奥巴马总统面临很多挑战，其中戒烟可能是最艰难的挑战之一了。50岁的奥巴马总统曾经一天要吸五次烟，而现在，他的最新的体检报告证实，奥巴马总统已经成功戒烟了。

Quitting smoking can help you sleep better, strengthen bones, prevent premature aging.

戒烟可以改善睡眠，强壮骨骼，预防早衰。