“弄清楚”的英语？

你一弄清楚了就给我打电话好吗？Would you call me as soon as you find out?人们开始四下察看，想弄清楚那声响来自何处。People began looking across to see where the noise was coming from.很难弄清楚使用的是什么样的标准。It is hard to make out what criteria are used....