About a dozen more officers were injured when the truck exploded and flipped over.
VOA: standard.2009.06.21
So the minus vector is the same vector flipped over, pointing the opposite way.
因此负矢量即为同一矢量的翻转,指向相反的方向
It's kind of like , where you had side A,side B and you just flipped it over when you wanted to change your mood so to speak.
VOA: standard.2010.06.18
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