One such material is asphalt, a substance often placed on top of buildings and used to cover road surfaces.

VOA: special.2010.03.02

We always had pumpkin pie, and if we were really lucky, a little bit of whipped cream on top.

VOA: special.2009.11.23

For years, researchers blamed muscle tension from tightening in the face, neck and the skin on top of the head.

VOA: special.2010.03.30

One hoodoo known as the Poodle looks like a poodle dog sitting on top of a long narrow rock.

VOA: special.2009.04.15

For several tense minutes, the astronauts of Gemini Six were sitting on top of a highly explosive mass of rocket fuel.

VOA: special.2009.07.01

The Americans had planned to use the Infrared Telescope Facility on top of Hawaii's Mauna Kea volcano the following night.

VOA: special.2009.08.25

They have an opening at the bottom for the fire and a place on top to put a pot.

VOA: special.2010.02.01

He had to make sure the great light on the top of light house would shine during the black storm.

VOA: special.2010.05.08

On the fourth day of battle, Marines fought to the top of Mount Suribachi, the tallest mountain on Iwo Jima.

VOA: special.2011.05.30

For example, you might see a W.W.E.wrestler jump off the ropes and land on top of his opponent.

VOA: special.2010.02.19

They have roots that stand in saltwater and look like cablesor ropes laid one on top of another.

VOA: special.2010.04.20

Today,scientists say a person dropped on the top of the mountain would live no more than ten minutes.

VOA: special.2010.06.30

Finally,on February twentieth, John Glenn climbed into his tiny spacecraft on top of the huge Atlas rocket.

VOA: special.2009.06.17

Or,they place long thin rolls of clay on top of each other and then make them smooth.

VOA: special.2009.09.09