A:
B:
C:
D:
若两个圆的周长比为3:7,则它们的面积比为( )
—Have you ever _______ to bring your homework to school?
—Yes. I _______ it at home once last term.
补全短语:____the park
已知△ABC中,点D在BC边上,且DC=6、S△ADC=15、∠B=45°,△ABD是等腰三角形,则S△ABD=____