完成短文每空一词Long ago,people did not have many choices about how

完成短文每空一词
Long ago,people did not have many choices about how to travel.They used to walk wherever they wanted to go.They used to carry heavy things on (1)_________ heads or backs.
(2)_________ time went by,people tried to find easier ways to travel.They learned that
(3)_________ could help.Camels,donkeys and horses could carry big loads on their backs.These animals (4)_________ also carry people.
To travel on rivers and lakes,people (5)_________ to build rafts and canoes.For travelling on the sea,people made strong (6)_________ ships.These ships travelled with the help of sails and wind.Most travel was still not fast.Soon one (7)_________ called the engine (发动机) changed travel.Gas engines were used in the first cars.The Wright brothers (8)_________ used a gas engine when they invented the first airplane.Travel became much (9)_________.
Today,people use many new types of vehicles (交通工具) to travel!New vehicles are fast.However,the story of transportation is not (10)_________ yet!People are always trying to bring us new types of vehicles.What do you think will be the next type of vehicle