aim后为什么加at

aim后为什么加at he studied hard,aiming at passing the exam.为什么aim要加ing?请详解. aim at Many ads aim at teenager.为什么? aim to 与aim at 的区别是什么?是aim to ,aim for ,aim at 三个 aim at 的用法 aim at是什么意思啊? AIM AT A SUCCESS aim sth at sb aim and aim at的区别? 关于英语中什么时候加S的问题,请指教一下.英语基础薄弱,望细致一点像“Censorship,which aims at purifying our mind,can refuce and even prevent indecent materials from minors”这句话,为什么aim后加s,mind不加s?.还 aim to、aim at、aim for有什么区别 Many ads__teenagers.A.are aimed at B.aim at 选哪一个?另一个为什么不行? aim at...用法及造句 The goverment has taken some measures .aming at cutting down the cost为什么不是to aim aim to和aim at的共同点,和区别! Aim at ,be aimed at的区别 The soldier raised his gun and calmly_____it at the enemy commander,fired.A.aiming B.aimed C.to aim D.aim为什么选A.