填空题
What was the new kind of power in the early 1800s?
It was ______.
填空题
When did the steamboat "New Orleans" make its first trip?
In ______.
填空题
In the past. who used steamboats?
The ______ and the manufacturers.
填空题
Why did manufacturers use the steamboats?
Because their trade depended on ______ transportation.
填空题
Who use steamboats today?
The ______.