一 We can always get much ______ on the Internet.
— Right. It's really useful.
A:clothes
B:books
C:information
半径为5cm的圆中,圆心角为72°的扇形面积为____ cm2.
如图,如图,共有____条射线.
.
下列加线字用法的解说不正确的一项是 ( )