But cement manufacturing produces around five percent of the carbon dioxide released by human activity worldwide.

VOA: special.2009.12.01

Furnace Creek is the largest area of human activity within Death Valley National Park.

VOA: special.2009.08.26

Some estimates suggest species extinction because of human activity is about 1,000 times faster than the natural rate of loss.

VOA: standard.2010.01.31

Most scientists believe the warming trend is mainly caused by human activity, especially the use of fossil fuels and the cutting down of forests.

VOA: standard.2009.12.09

"Our relations have been transformed, and today they encompass cooperation in all areas of human activity."

VOA: standard.2009.11.25