The great wall of china to keep out the Mongolas
China has used the Great Wall as a barrier.
China and the U.S.
it helped by providing a natural barrier to keep out invaders
china kept out the mongols with the Great Wall
It was built to protect the country from raids.
to keep out the Mongol invaders
The Wall.
To keep the US from getting involved with other countries. He failed.
to keep invaders out.
yes
There were few Mountains or other natural barriersto keep invaders out of Eastern Europe.
we trade with other countries to get goods that we dont have in our country, to keep contact and to make friends with the other countries foe situations in the future