When social scientists study economic development, they look at a lot of things.

Scientists study what happens to people when they live in space.

Scientists study these "risk factors" and put them all together with numbers.

Scientists from all over the world have studied these trees.

But he said that scientists studying the problem might find the reason to be more complex.

Political scientists from all over the nation are studying the Speaker.

Scientists have been studying cell phone use and possible health effects for many years.

Scientists have been studying the impact of climate change and water use.

Scientists have not studied all the stages very well yet.

Scientists studying the solar system say they have found the best evidence of water out there.