Which is an example of the strong force in action?

a battery-powered radio produces sound.
a magnet keeps a cabinet door closed.
the sun pulls on earth as earth moves around the sun.
the protons in the nucleus of a carbon atom are held together.

Can someone me with questions 15 to 17 plz.

Why did southern business leaders want to increase the number of slaves

Which of the following contributes to the structural rigidity of cellulose? adjacent glucose polymers are stabilized by hydrogen bonding. glucose residues are joined by (α1→4) linkages. cellulose is a highly branched molecule. the conformation of the glucose polymer is a coiled structure.