单项选择题 Identify the fallacy in the following statement: Every time the cheerleaders have worn blue ribbons, the basketball team has won. If the team wants to keep winning, the cheerleaders should continue wearing blue ribbons.

多项选择题 按钮的形状主要包括( )( )、( )( )、( )( )、( )( )、等。() A、矩形 B、圆形 C、胶囊形 D、圆角矩形

单项选择题 金属铁具有强磁性的原因是其原子磁矩之间具有正的交换作用。