题目

The Blacks are American tourists. They visit in Beijing now. This is their first visit to China. They are going to stay in China for three months. They want to visit some big cities and villages. They hope to learn some Chinese, too.Mr. Black is a taxi driver. He likes to drive in Beijing. Mrs. Black is a school teacher. She is visiting a city school today and a village school tomorrow. Their daughter is a middle school student. She is going to meet some Chinese students.They are taking a lot of pictures in China. When they return to America, they are going to show the pictures to their friend一个几何体的三视图如图所示（单位：），则该几何体的体积为（ ）A． B． C. D．