阅读些列四篇短文，从每小题后所给的A、B、C、D四个选项中，选出你最佳选项，并在答题卡上将该选项涂黑。
A
Sometimes, the simplest ideas are the best．For example, to absorb heat from the sun to heat water, you need large, flat, black surfaces．One way to do that is to build those surfaces specially, on the roofs of buildings．But why go to all that trouble when cities are full of black surfaces already, in the form of asphalt （柏油） roads?
Ten years ago, this thought came into the mind of Arian de Bondt, a Dutch engineer．He finally persuaded his boss to follow it up．The result is that their building is now heated in winter and cooled in summer by a system that relies on the surface of the road outside．
The heat-collector is a system of connected water pipes．Most of them run from one side of the street to the other, just under the asphalt road．Some, however, dive deep into the ground．
When the street surface gets hot in summer, water pumped through the pipes picks up this heat and takes it
