In impoverished Yunnan Province in southwestern China, a confrontation is brewing between economic growth and habitat preservation-and authorities are sending mixed signals about their intentions.

In Little League dugouts, community parks, professional athletic organizations, and international soccer leagues, on college campuses and neighborhood playgrounds, even in residential yards, the question being asked is "grass or plastic?' The debate is over synthetic turf, used to blanket lawns, park spaces, and athletic fields where children and adults relax and play; the questions are whether synthetic turf is safe for human and environmental health, and whether its advantages outweigh those of natural grass.

the strongest acid: The world's strongest acid, at least a million times more potent than concentrated sulphuric acid, has been made in a lab in California. It is also one of the least corrosive.