题目

—Look, the building ________ top we can see here is our library. —Oh, it is very beautiful. A . that B . what C . which D . whose 答案：D有个零件形状如图，这个零件的体积是多少立方厘米？如果1立方厘米铁的重量为7.8克，用铁制成的这种零件有多重？