A strong topic sentence is thorough and lengthy.
specific and concise.
general and brief.
scientific and detailed.

A strong topic sentence is general and brief.

Explanation:

The topic is general enough to allow for the development of support and explanation with more specific points in the rest of the paragraph.

It is brief--  like a signpost or headline to help the reader understand where the paragraph is headed and summarize its main idea.

different routes can lead to sammy to different places, with different roads.   if you check a map, you can see the routes.   try to make connections of the places and count how many there are.   hope this : )

its probably a noun because a noun is a person place or thing