Big Ben is not the name of a man. It's the name of a big clock in London. This clock has four faces. So, no matter(无论)where you stand, you can read the time on the face of Big Ben. Each face is the size of a bus. The hands are about four metres long. If you go to London, you may want to visit the Houses of Parliament(英国国会大厦). In that place you will find Big Ben sits at the top of the clock tower in the Houses of Parliament. You will probably hear it and see it. The big clock makes such a loud noise. It goes every quarter of an hour. Big Ben has been the most famous symbol(标志)of  London

1954年9月21日《人民日报》报道：“（20日）下午五时五十五分，执行主席宣布表决结果：投票数共一千一百九十七张，同意票一千一百九十七张。这时，全场欢腾，全体起立，为这个伟大文献的诞生而热烈欢呼。”投票通过这部“伟人文献”的会议是（    ）

有如下几个结论：
①相关指数$R^2$越大，说明残差平方和越小，模型的拟合效果越好；
②回归直线方程：$\stackrel{\wedge }{y}=bx+a$一定过样本点的中心$\left(\stackrel{-}{x},\stackrel{-}{y}\right)$；
③残差点比较均匀地落在水平的带状区域中，说明选用的模型比较合适；
④在独立性检验中，若公式$K^2=\frac{n{\left(ad-bc\right)}^2}{\left(a+b\right)\left(c+d\right)\left(a+c\right)\left(b\left|+d\right|\right)}$中的|ad-bc|的值越大，说明“两个分类变量有关系”的可能性越强.
其中正确结论的个数有（   ）个.