Toddler Tourism

"Mum-Mee", comes the voice of the Automatic Question Generator in the back seat of the car, "Who makes water?"  "Well darling", I reply, trying to give myself an air of Professor Brian Cox but probably sounding a bit more like Winnie the Pooh, "Nobody makes water.  Water just IS".  "What?", says the AQG, totally dissatisfied with my flaky answer. "Weeel…