已知 $a+b=-3$ ， $ab=2$ ，则 $(a-b{)}^2$ 的值是____.

   Hi, I'm John. I had a good time last Sunday. I went to the nature park with my family, We saw the animals. The animals were so cute. I loved them verymuch. I took many pictures. In the afternoon, we went to the cinema. The film was so fun. Then we went home. My mother cooked good food for me. I was so happy. What about you? What did you do last weekend?

下句中，只有一处错误，请找出并改正。

What if I won't know anyone?

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