下面等边三角形的周长是( ____ )厘米。
A市至B市的航线长1200千米,一架飞机从A市顺风飞往B市,需要2小时30分,从B市逆风飞往A市需要3小时20分,则无风时飞机的速度是( )千米/小时.
— I'm hungry. ________ there any bread in the fridge, Mum?
— None, but we have cakes. Would you like to have one?