Mathway.com solves all kinds of math homework problems with step by step explanations.
15
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
16