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

VOA: special.2009.06.22

By this time, Jackson had decided that Van Buren would be the best man to follow him as president.

VOA: special.2009.01.01

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

From that time on, the San Francisco policemen showed respect to Joshua Norton by giving a military salute.

VOA: special.2009.12.14

Experts say by the time a farmer discovers that something is wrong, it is already too late.

VOA: special.2009.09.21

"My!" she said, "That was a good morning.By the time you wash,we'll be ready to eat!"

VOA: special.2009.02.14

This time, he stayed until the end of April, by then he had so many furs that he had to leave his traps behind.

VOA: special.2010.06.26

By that time, the use of the telegraph meant that newspapers could report on recent events.

VOA: special.2009.04.20

He thought that this was evidence that the bottom of the ocean had been lifted up by powerful geological forces over long periods of time.

VOA: special.2009.02.25

It says an explosion or explosions by comets could explain the disappearance of many animals and human beings who lived in North America at that time.

VOA: special.2009.01.20

By the time of her death in nineteen twelve, she had begun a revolution that led to the right of women to do responsible work for society.

VOA: special.2009.07.26

By that time,however, the American Civil War really was over.

VOA: special.2010.01.14

By that time, the patient may already be dead.

VOA: special.2009.03.25

"We can say that 50 percent of the burden of obesitycan be contributed by having no leisure time physical activity."

VOA: standard.2010.08.10