In a synthetic organic chemistry reaction, a 1-bromobutane (C4H9Br) undergoes both nucleophilic substitution and elimination reactions by using sodium hydroxide (NaOH) as a reagent in an ethanol solvent. Analyze the reaction pathway and predict the major products formed under two different conditions: one where the reaction is allowed to proceed at room temperature (for nucleophilic substitution) and another where the temperature is raised to 70°C (favoring elimination). Which pair of competing reactions will give the predominant products under these conditions?