July 23, 2015 â Teens using marijuana for medical reasons are 10 times more likely to say they are hooked on marijuana than youth who get marijuana illegally, a new study shows. The study is the first to report on a ... Slow to Mature, Quick to Distract: ADHD Brain Study Finds Slower Development of Key Connections.
Define prehistoric. prehistoric synonyms, prehistoric pronunciation, prehistoric translation, English dictionary definition of prehistoric. also preÂ·hisÂ·torÂ·iÂ·cal adj. 1. Of, relating to, or belonging to the era before recorded history. 2. Of or relating to a language before it is first recorded...
adj. Of or relating to the cultural period of the Stone Age beginning around 8,000 bc in the Middle East and later elsewhere, characterized by the development of agriculture and the making of polished stone implements. n. The Neolithic Period. Also called New Stone Age.