Two things that made travel difficult for humans was a lack of natural speed and the lack of knowledge in correcting this. Once humans were able to ride animals and build vehicles, they become very efficient at travelling.
water and mountain
They travel by rockets
What are the two mountain ranges that made land difficult to travel?
by walking
the pyramids
the wheel
the oceans
life was difficult because they did not have most of the things we hav today
It was hard to cross the Appalachians and it made travel difficult and dangerous
hunt for evideace in the ground and study things made by humans
The jet engine made the world smaller by making travel time shorter. Also,helped to get humans into outer space. These are just a few things the jet engine did.
because we are made from blood and a robot is made from metical things we are not like that