The line in between indicates that there is a single bond connecting the two carbon atoms. Atoms can be bonded via single bond, double bond and a triple bond. Among the three, the single bond is the weakest, but it allows for more atoms to connect to it because it leaves 3 more pairs available for bonding.
So in summary, among all the bonds that was given, a c-c bond is the weakest and the longest.
A. As you make more and more of one good or service, you will also make more and more of another.
This is what I found!!! I hope this helps!!!!