【正确答案】正确答案： The Solar Water Heater Solar water heaters are used around the world and are not very difficult to build. / There are two parts to the solar water heater. / One part is made of a sheet of metal painted black. / Black surfaces become hotter in the sun than surfaces painted any other color. / The second part of the solar water heater holds the water for the system. / This storage tank can be a container that holds about one hundred liters. / Two rubber pipes are attached to the water storage tank. / One pipe lets water flow into the system. / The other lets water flow out. /