Ninety percent of the cases of polio are in security-vulnerable areas.

Never before in history has innovation offered promise of so much to so many in so short a time.

Unfortunately, the highly curious student is a small percentage of the kids.

If you think your teacher is tough, wait till you get a boss.

Finding information is either a software question or a question of how much information is online.

The next big invention that will change the way we live should be things like ways of generating energy like electricity.

Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it's about 20 tons. For people in poor countries, it's less than one ton. It's an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero.