15 The weather in Suiping

There is more water in coastal areas, and the specific heat capacity of water is greater. During the day, compared with the quality of water and gravel, the absorbed heat is the same, and the temperature of water rises less.

The same heat is released at night, and the water temperature drops less, which makes the temperature difference between day and night in coastal areas smaller.

As can be seen from the table, the temperature difference in city A is small, so city A is a coastal city in Shanghai. B the temperature difference is large, and B is the inland city of Zhengzhou.

So the answer is: Shanghai; In the coastal cities of Shanghai, the specific heat capacity of water is large, and the temperature changes little under the same endothermic and exothermic conditions.