Ella is interested in combining substances to form a new material.
 She read about some of the products chemists have discovered. She learned that sometimes synthetic materials are created accidentally. For instance, a chemist working on plastic gun sights synthesized a very sticky material accidentally. Which product had he accidentally made?
 A. a coil spring toy
 B. a heavy-duty adhesive glue
 C. a new sweetener
 D. a non-stick surface
 please hurry