题目

---______do you usually go to school? ---By bus.A.  How long   B When    C How   D How often 答案：C解析:略19．某几何体的三视图如图所示，则该几何体的体积为（　　）A．3$\sqrt{3}$B．$\sqrt{3}$C．$\frac{4}{3}$$\sqrt{3}$D．$\frac{5}{3}$$\sqrt{3}$