A:闭合 S1、S3,断开S2
B:闭合S1、S2,断开 S3
C:闭合 S2、S3,断开S1
D:闭合S2,断开 S1、S3
12345679×9=____
12345679×18=____
12345679×27=____
12345679×36=____
12345679×45=____
12345679×54=____
你发现了什么规律?
As well as ________ all his homework, he helped his mother with a good cleaning around the house.
溶液一定是( )
①无色的、透明的 ②均一、稳定的 ③纯净物 ④混合物.