But now the nature of the game has changed, scientists say.

But scientists say they don't know what set off the problem.

Iraq is also able to make its own growth media, scientists say.

Society as a whole must answer those questions, he and other scientists say.

But another reason, scientists say, is simply that no one thought to look.

Find out what the scientists are saying and do something to help, even if it's only very small.

And if scientists say your treatment doesn't work, you simply tell them that they're wrong.

Still, some scientists say it is best not to play with fire.

And social scientists say it is important to ask about the issue several ways.

Some scientists say it is best for the land to be left alone.