Answer:
The line a runner strives to reach
Spies and detectives do this to phones and musical shoes make this sound.
What is this Mexican dish consisting of a tortilla rolled around a filling, typically of beans or ground or shredded beef?
What instrument can make any sound and be heard but not touched or seen?
I have eighty-eight keys but cannot open a single door? What am I?
What is lighter than what it is made of?