single most significant single most valuable single mother single mother who single motherhood single mothers single motion single motor single mouse single move single movement single movie single mum single municipality single muscle single mutation single mutations single nail single name single named single narrative single nation single national single natural single nave single needle single negative single nerve single network single neuron single new single news single newspaper single night single node single noise single note single notes single nozzle single nuclear single nucleotide single nucleotide polymorphisms single number single object single objective single occasion single occupancy single of all time single of the album single of the week single of the year single off single off the album single offer single office single officer single official single offspring single oil single old single olympic single on itunes single one single one has single one of them single one of us single one of us has single one of you single one of you has single online single only single open single opening single operating single operation single operator single opportunity single optical single option single or a double single or divided single or double single or double occupancy single or double room single or dual single or married single or multi single or multiple single or twin single order single organ single organisation single organism single organization single orifice single origin single original single other single ounce