1×9 + 2 =" 11" 12×9 + 3 =" 111" 123×9 + 4 =" 1" 1111 234×9 + 5 =" 11" 11112 345×9 + 6 =" 111" 111
A:1 111 111
B:11 111 111
C:111 111 111
D:1 111 111 111
16×6-6×6=____
下列是某同学自主学习时收集的图片。从中可见他学习的主题是( )