A:4π3cm3
B:8π3cm3
C:4πcm3
D:20π3cm3
She asked her father for ____(permit) before applying for the job.
下列几何体中,正视图是矩形的是( )
运用杠杆的知识判断,如图中最适合剪断铁片的剪刀是( )