题目

Many years ago, there lived a very rich man who wanted to do something for the people of his town. But first he wanted to _______ whether they were good enough to get his help. So he placed a very large stone in the center of the main _______ into town. Then he hid behind a tree and waited.Soon an old man came along _______ his cow. “Who put this stone in the center of the road?” said the old man, _______ he did not try to move the stone away. Instead, he passed around the stone and continued on his way. Another man came along and did the same _______; then another came, and another. All o一个三角形的底是15m，高是底的1.4倍，这个三角形的面积是[     ]A．21m2B．315m2C．157.5m2