Mister Lowell's theories were based on what were serious scientific studies of that time.

VOA: special.2010.07.11

Roy Acuff was perhaps the most popular Opry artist of that time.

VOA: special.2010.05.17

Other scientists have shown that sun spot activity can be measured in periods of time that last about eleven years.

VOA: special.2009.09.29

Doctors say that over time the damage interferes with the natural exchange of oxygen and carbon dioxide in the lungs.

VOA: special.2010.06.23

That is the amount of time it took Associated Press photographer Joe Rosenthal to capture a historic image on film.

VOA: special.2010.05.31

The researchers also found tools used by the Clovis culture, a group of human beings who lived at that time.

VOA: special.2009.01.20

He died last year. By that time, hundreds of thousands of the filters were in use in developing countries.

VOA: special.2009.06.22

Now it is spring in the northern part of the world so it is time to celebrate that season.

VOA: special.2010.03.15

That is the time of year when lilac plants burst into flower throughout much of the United States.

VOA: special.2009.12.31

It is that time of year again. Warm weather means outdoor music festivals and one of the biggest is happening right now.

VOA: special.2009.05.01

Much of the air traffic at that time was between Croydon Airport and Le Bourget Airport near Paris,France.

VOA: special.2010.04.18

At that time, schools of higher learning usually were supported by people interested in profits from their investment.

VOA: special.2010.06.27

Researcher Laura Nauman noted that we live in a time of social media, and personal photographs are everywhere.

VOA: special.2009.11.24

If the price of shares of a stock hits bottom that might be the time to buy it.

VOA: special.2009.09.20