Complete the conversation. Then, listen and check your answers. 

didn't        travel        use        used        used to

Sue: Why did people (1) __________ to travel by horse?

Aki: Well, there (2) __________ use to be other transportation.

Sue: OK, but did everyone use to (3) ____________ that way?

Aki: No, in some parts of the world, they (4) ___________ use camels, not horses. Why are you so interested in how people (5) ____________ to travel?

Sue: I'm writing about transportation in the past for my history class.