(2) Through the analysis of the data in the table, it can be known that for the same quality of sand and water, the time spent by sand is less than that spent by water in the process of heating up 10℃; Under the same heating conditions, it takes more time, indicating that more heat is absorbed.
(3) As can be seen from the chart, water at the same temperature will last longer; In other words, if heated for the same time, the temperature of water will rise less than that of sand.
(4) At the beginning of heating, the sand is unevenly heated (the bottom is heated more and the top is heated less), which may cause the thermometer reading on the left to be smaller than that on the right.
So the answer is: (1) How much heat is absorbed?
(2) greater than.
(3) sand.
(4) The sand is unevenly heated.