(20 14? As the picture shows, Xiaodong is exploring "comparing the heat absorption capacity of water and iron ore". In the experiment, water and iron ore with the same initial temperature were selected. A. There are two methods to compare the heat absorption capacity of water and iron ore: heating for the same time and comparing the temperature changes; Raise the same temperature and compare the heating time. Therefore, the method of controlling variables is needed, so A is correct.

B, the temperature, quality and heating time needed for the experiment, so the measuring instruments needed are thermometer, balance and stopwatch. Therefore, B is correct.

C, using the same alcohol lamp to evenly heat the metal box containing water and iron ore with equal mass needs to be heated at the same temperature, and its heat absorption capacity is compared according to the heating time, so C is wrong.

D. It is incorrect to say that the temperature difference between day and night in coastal areas is greater than that in inland areas, so this experiment cannot be confirmed, so D is correct.

So choose C.