The pistons go up and down as a person stands on lever devices treadles and uses a natural walking motion.

VOA: special.2009.08.17

There,on Easter morning, people walk up and down Fifth Avenue after church services to enjoy the spring weather.

VOA: special.2009.12.20

They sailed up and down the Atlantic Coast and stole anything of value from other ships.

VOA: special.2011.07.26

Then he got up, found a long stick and walked up and down the river bank.

VOA: special.2010.06.26

From a cave room you can see far up and down the canyon and imagine what life was like there seven hundred years ago.

VOA: special.2010.07.05

We continue on our trip, driving on a winding road up and down the Black Mountains.

VOA: special.2010.08.23

I keep my mind active and coming to school three times a week, and walking up and down the steps, that kept me physically able."

VOA: special.2010.07.16

Electromagnetic energy travels almost like an ocean wave - up and down,up and down.

VOA: special.2010.12.08

A big, heavy man was walking up and down in the hotel lobby.

VOA: special.2009.01.17

It makes them jump up and down, and sing it with you.

VOA: special.2010.06.13

A big,heavy man was walking up and down in the hotel lobby.

VOA: special.2010.06.12

Mist can take you on a boat ride up and down the river so you can see the animals as they come to drink or play in the water.

VOA: special.2009.08.19

Ad sales have always gone up and down with the economy.

VOA: special.2009.03.21

Voyager's long wings moved up and down as the winds changed.

VOA: special.2010.10.06