1 Six rain gauges are spread throughout a city. The mean height of water in these gauges is 1.8 centimeters after a rainy day. Which statement must be true? 
 A All of the rain gauges would have 1.8 centimeters of water, if distributed evenly. 
B At least one of the rain gauges has exactly 1.8 centimeters of water. 
C All of the rain gauges have 1.8 centimeters of water.