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    I'm Chinese ，but I am in England now. I can speak English. But I sometimes make mistakes with English. It was sunny yesterday. My class went to the park. I said，“Let's fly cats in the park. ”My classmates all laughed. I didn't know why. Then my teacher said，“Cats are animals. We can't fly them. But we can fly kites. ”“I know my mistake. I wanted to say kites，not cats. ”I said. Then we laughed again. That was funny.

${}_{26}^{56}F{e}^{2+}$微粒中的质子数是　____ ，中子数是　____ ，核外电子数是____