Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
Most reptiles have good eyesight and a keen sense of smell. Snakes smell scents in the air using their forked tongue (see Figure below ). This helps them locate prey. Some snakes have heat-sensing organs on their head that help them find endothermic prey, such as small mammals and birds. Staring into the Beautiful Cold-Blooded Eyes of Reptiles at http://www. environmentalgraffiti. com/news-reptile-eyes is a pictorial display of numerous reptile eyes.


Question: Snakes use what anatomical structure to smell scents in the air?
forked tongue
Their forked tongue.