若扇形的半径为9,圆心角为120°,则它的弧长为____ .
多音字组词
悄qiāo____ qiǎo____ 好hǎo____ hào____
The paper is made __________ wood and the desk is also made __________ wood.
下列关于亚洲地形、地势、河流的叙述,正确的是( )