Consider four mixtures of organic compounds with given boiling points for pure material: dichloromethane (bp 40oC) and 1-butanol (bp 117oC), dioxane (bp 101oC) and diethyl ether (bp 35oC), chlroethane (bp 12oC) and toluene (bp 110oC), diethyl ether (bp 35oC) and dichloromethane (bp 40oC). Which of them can NOT be separated by SIMPLE distillation?