$△$ABC是边长为2的等边三角形，已知向量$\overrightarrow{a}$,$\overrightarrow{b}$满足$\overrightarrow{AB}=2\overrightarrow{a},\overrightarrow{AC}=2\overrightarrow{a}+\overrightarrow{b}$,则下列结论中正确的是____。（写出所有正确结论得序号）.
①$\overrightarrow{a}$为单位向量；②$\overrightarrow{b}$为单位向量；③$\overrightarrow{a}$⊥$\overrightarrow{b}$；④$\overrightarrow{b}$//$\overrightarrow{BC}$ ;⑤ （4$\overrightarrow{a}$+$\overrightarrow{b}$）⊥$\overrightarrow{BC}$。

    Long long ago, there ____ a king. He ____ new clothes very much. There ____ two ____.  They can make magic clothes. ____ people can see it. But foolish people can't. The king ____ through the city with new clothes. A lot of people looked at him and ____. A little boy ____ at the king and ____ "Ha! Ha! The king isn't ____ clothes!"