The boiling point of a substance in city eight is found to be 145°c. the boiling point for the same substance in city b is 141°c. which city rv is at a higher elevation? how do you know?

The relationship between boiling point of liquid and elevation is inverse. Means, with increase in altitude the boiling point will decrease. This is because with increase in altitude the atmospheric pressure will decrease, as boiling point is temperature at which vapor pressure of liquid becomes equal to the atmospheric pressure. 

Hence, the city where boiling point of specific liquid is 141 °C is at higher elevation. And the liquid with boiling point of 145 °C is experiencing higher atmospheric pressure due to less altitude of the city it is present in.