A calf is a young cow. A young female cow, especially one that has not yet had a calf, is called a heifer: H-E-I-F-E-R.

VOA: special.2009.07.21

So if I print e to f of soccer, it will print the string football.

如果我要显示soccer的e到f变换的话，打印出来的就是football了。

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