The following sentences should be included in a summary of the text:
- Fitch's boats cost too much to make.
- John Fitch combined old methods of constructing boats with new technology to create the first steamboats.
The sentence about Robert Fulton is also relevant, but it focuses more on the outcome after Fitch's contributions rather than summarizing Fitch's achievements directly. The statement about riding a steamboat is not relevant to the summary.