>>970
うーむむむ？(・o・)

しつもん
1, They took the narrow stairs THAT LED up to the top of the building.
2, They took the narrow stairs LEADING up to the top of the building

ねいちぶ（..と思う）
Exact same meaning. Both are frequently heard. I prefer #2, but it's just a personal preference. I prefer one word to two, when the meaning is the same.