Find the odd sentence out from the given sentences:
- People who study children's language spend a lot of time watching how babies react to speech they hear around them.
- They make films of adults and babies interacting, and examine them very carefully to see whether the babies show any signs of understanding what the adults say.
- They believe that babies begin to react to language from the very moment they are born.
- Sometimes the signs are very subtle – slight movements of the baby's eyes or the head or the hands.
- You'd never notice them if you were just sitting with the child, but by watching a recording over and over, you can spot them.