ISMAIL ABBA and AFOLABI SOTUNDE USAMA Aminu was one of the lucky ones. He managed to escape when gunman abducted more than 300 pupils from his school in northwestern Nigeria. "When I decided to run they brought a knife to slaughter me but I ran away quickly," he said, sitting on a mat and speaking softly as he described how he had been in bed at the all-boys school in Kankara when he heard gunshots on Friday night. At first, he said, the boys thought the commotion was from soldiers trying to protect them, but the attackers, armed with AK-47s,…