claim: Levoamphetamine increases concentration.
evidence: N2 , N-2 may be  :. N ₂ , the chemical formula for nitrogen gas. nitrogen gas. nitrogen gas. N2 is the United States Navy term for a senior military intelligence officer. United States Navy. United States Navy. N2 diagram , a function to function data interchange. N2 diagram. N2 diagram. N 2 Gether Now , a 1999 song by nu metal band Limp Bizkit. N 2 Gether Now. N 2 Gether Now. DSC-N2 , a 2006 Sony Cyber-shot series digital camera. DSC-N2. DSC-N2. N2 , a postcode district in the N postcode area. N postcode area. N postcode area. NicoNico , N2 company logo for niconico live video. NicoNico. NicoNico. The fourth level in the Japanese Language Proficiency Test. Japanese Language Proficiency Test. Japanese Language Proficiency Test. N2 Global Solutions Inc. a cognitive energy management system