题目

 Jenny, the new comer, has earned not only the trust of her classmates but also ______ of her teachers. A. one               B. ones            C. that             D. those 答案：C如图，中，，在三角形内挖去半圆，圆心在边AC上，半圆与BC、AB相切于点C、M，与AC交于点N，则图中阴影部分绕直线AC旋转一周所得旋转体的体积为 ．