A sore throat is caused by inflammation or infection of the throat and nearby areas. Strep throat is the most familiar cause of this, but other infections can cause it too. Your immune system is attacking something in the area and causing inflammation.
The key to making a paper airplane that flies the farthest is in the design. You want to make sure that your plane has a good center of gravity and enough weight to keep it stable, but not so much weight that it will drop out of the sky. The ideal paper planes are those that are made with stiff paper and have a tapered nose.