Which invention changed the way of travel?

What is common to all the means of transport on land?

We can reach any place easily by a :

Which is important?

What do vehicles emit into the air?

How many wheels does a bullock cart have ?

Which of the following can take us to very far distance in a very short time?

People sits on carts drawn by bulls, horses or camels in:

Which mode do we use to go to places nearby our home?

Which carries passengers and goods from one country to another on oceans?