Twenty feet -- that's six meters. Other suggestions include putting more distance between you and the device and using good lighting.

VOA: special.2011.08.01

Too much time inside the house using a computer or watching television can cause someone to get cabin fever.

VOA: special.2010.03.28

NASA scientists using the Kepler space telescope also announced the discovery of six planets orbiting a star called Kepler-11.

VOA: special.2011.02.09

In addition,using the lambs costs much less than hiring workers to prune the vines for seven weeks in the summer.

VOA: special.2009.07.14

Using the same amount of land, the new wheat variety could produce three to four times as much food.

VOA: special.2009.11.10

Anders Wilhelmson says people can get back ten times what they paid by using the resulting fertilizer to grow vegetable gardens.

VOA: special.2010.03.15

The United States did,too. In eighteen seventy-three, Congress passed a law that stopped the government from using silver as money.

VOA: special.2010.06.17

For many years after Mister Harrison's work was completed, the idea of using a clock to learn longitude was rejected.

VOA: special.2010.07.14

The satellite images may not show what the farmers are using the trees for, but trees provide nuts,fruit, wood and other products.

VOA: special.2009.09.01

He offered the pirates a deal. He suggested the pirates could escape using one of the ship's lifeboats.

VOA: special.2009.05.27

Bill invented the method of using a hot branding iron to permanently put the mark of a ranch on a cow's skin.

VOA: special.2011.06.11

But in nineteen ninety-one, Democrats accused President George H.W.Bush of using the last such speech for political purposes.

VOA: special.2009.09.17

Professor Ervin says this means that some farmers are again using the more toxic herbicides to control weeds.

VOA: special.2010.04.27

But experts generally advise against using the drug if more than three hours have passed after the first signs of a stroke.

VOA: special.2009.09.22