设函数y=$\sqrt{1-x^2}$的定义域为A，关于x的不等式mx﹣2＜0的解集为B．

（1）当m=3时，求A∪B；

（2）当m＞0时，若A⊆B，求m的取值范围．

中国古代历史浩如烟海，你知道楚汉战争中“鸿门宴”的故事吗?抗战胜利后，在重庆又上演了一场惊心动魄的“鸿门宴”-一重庆谈判。读下则电文，完成下列问题：
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 ①由方程 =2去分母，得x-12=10;

 ②由方程 x= 两边同除以 ，得x=1;

 ③由方程6x-4=x+4移项，得7x=0;

 ④由方程2- 两边同乘以6，得12-x-5=3（x+3）.

 错误变形的个数是（  ）个． 

    This is a s____  of twin brothers, Justin and Paul. Their friend Susan calls them for h____ . Justin and Paul drive to Hill Building q____ . Three man in police uniform p____  them into a green van. They are not p____ . They are the robbers. The twin brothers aren't a____ . Paul opens the back door of the van w____  a knife. They take different r____  to the police station. They meet the robbers a____  in the police station. They are s____ . The policemen stop the van because the back door of the van is open.