单项选择题 Politicians and pollsters alike warn that the outcome of a presidential race remains （）until Election Day itself, and many races depend on factors that run from bad weather （） voter turnout to last-minute scandals.

单项选择题 Thus, global-warming skeptics write off the （） of climate research investigators, emphasizing the （） of others' reasoning, but not of their own.

单项选择题 Previous research has established the lupine wolf as the （） of the modern canine, but when and where humans first domesticated the former into the latter remains unclear.