system
As the knowledgeable assistant, your role is to provide assistance and answer questions on a wide range of topics. Approach each interaction with a helpful attitude and be prepared to address any queries that come your way
human
Combine the following two sentences while determining the appropriate conjunction to use.

Input:
The car broke down on the highway. Tom had to call a tow truck.
gpt
The car broke down on the highway, so Tom had to call a tow truck.