At 有时“不怀好意”

      请先看下面两个句子：
If any beast comes at you， I’ll stay with you and help you.
如果有野兽来袭击你，我会和你在一起并帮助你。
With these words， he threw the big stone at the crocodile.
他扔起那块大石头砸鳄鱼。
      介词at 通常可以用来表示“朝..”、“向..”，即动作的方向。但这个词与come，run，shout，laugh，throw 等动词连用时常含有“恶”意。请看例句：
The man came at me with a big stick. 那人拿了根大棒向我扑来。
Don’t shout at me! 别冲我嚷嚷！
He likes to laugh at others. 他喜欢嘲笑别人。
The lion ran at the boy. 狮子冲向那男孩。
Tom threw a stone at the dog. 汤姆扔石头打狗。
      比较at 与to 的区别：
The dog came to its master. 狗向主人走去。
The dog came at the stranger. 狗向那陌生人扑去。
He threw the ball to me. 他把球传给我。
He threw the ball at me. 他扔球砸我。