(题干同试题11)
How does our body heat offer us the service?
①The heat makes underground water tanks become warmer.
②The heat is passed on to enter an office building.
③Use a piece of equipment to collect our body heat.
④The temperature of the building is higher.

由第三段中“Swedish scientists are using a piece of equipment to catch the warm air and guide it to heat underground water tanks (箱). The warmed water from these tanks lets the heat enter an office building about 60 meters away. As a result, the building’s energy costs are down by 20%.”可知，第一步是先用一个设备储存体热，第二步是体热将水箱变热，第三步是将热能输送到办公楼，第四步，室内温度增高。所以正确答案为D。

略