How will you help with the activity? We will ______ leaflets to ask people to take part.
A:put out
B:give out
C:found out
D:cut out
常见的永久磁铁的组成为BaFe12O19与曾用于雷达微波过滤器里的钇铁榴石(Y3Fe5O12)均为铁氧体。钇(Y)是稀土元素,常为+3价。它们的组成中所含铁元素的价态应为 ( )