求向量组 $\alpha_1=\left(\begin{array}{l}1 \\ 1 \\ 2 \\ 3\end{array}\right), \alpha_2=\left(\begin{array}{l}1 \\ -1 \\ 1 \\ 1\end{array}\right), \alpha_3=\left(\begin{array}{l}1 \\ 3 \\ 3 \\ 5\end{array}\right), \alpha_4=\left(\begin{array}{l}4 \\ -2 \\ 5 \\ 6\end{array}\right)$ 的秩和一个极大线性无关组,并把其余向量用极大线性无关组线性表出.