HELP PLEASE I GIVE 30 POINTS +MARK BRAINLIEST!!!!!

DIRECTIONS Look at each set of four vocabulary terms following each
number. On the line provided, write the letter of the term that does not
relate to the others.

______ 6. a. Clermont b. Robert Fulton c. Tom Thumb d. steamboat
______ 7. a. Tom Thumb b. steamboat c. Peter Cooper d. locomotive
______ 8. a. coal b. steel c. fuel d. wood