Question

and biking. no cars are allowed.
these routes were made for trains many years ago. once
the rails are removed, the paths are perfect for bicycles.
you can ride these
ail trails\ through cities and from one
city to another. the longest rail trail, in missouri, is 225
miles long!
a cyclist travels across an old railroad bridge on a rail trail.
fill in the blanks to explain why the
author thinks rail trails are good for
bikers.
rail trails are
fast
rare
safe
because they
let bikers avoi ets. the trails
are built on ol hat trains
no longer use. s can ride for
miles without coming near

Explanation:

1. For the first blank: The text says "No cars are allowed" on rail trails, so they are "safe" for bikers (as avoiding cars makes it safe). "Fast" doesn't fit the context of avoiding cars, and "rare" is irrelevant.
2. For the second blank (the structure part): The routes were made for "trains" originally, so the trails are built on old paths that trains no longer use.
3. For the last blank: Since no cars are allowed and it's a trail for bikes, bikers can ride without coming near "cars" (as the first part mentions avoiding cars, and the trail is for bikes away from car traffic).

Answer:

First blank: safe
Second blank (the vehicle): trains
Last blank: cars

(Note: The exact blanks' positions might need adjustment based on the dropdowns, but the logic is: Rail trails are safe because they let bikers avoid cars. The trails are built on old paths that trains no longer use. Bikers can ride for miles without coming near cars.)