数学求平均值公式简介:If you meet a strange dog on the street, no matter how afraid you are that it will bite you, you must not be afraid to look at it. Otherwise, if you show any timidity, it might pounce on you.
If you meet a strange dog on the street, no matter how afraid you are that it will bite you, you must not be afraid to look at it. Otherwise, if you show any timidity, it might pounce on you.