Select the best word or phrase that completes each sentence…

Select the best word or phrase that completes each sentence (alkynes, enol, keto, with, without, aldehydes, tautomers, acetylide, ionic, resonance, higher,  lower,  decreases, increases,  rotation, alkenes, ketones, carboxylic acids, nitrogen, bromine, chlorine, oxygen, cis, trans, anti, dihydroxylation, epoxidation, oxidative, reduction, syn,  odd, even, hydroboration, regioselective, above , below, allylic)   ………………….  anions are strong nucleophiles that react with primary alkyl halides by an SN2 mechanism.  Complete word/phrase and correct spelling (verbatim) is required. No partial credit.