Hi Lawrence, "Situation" can refer to the location of a place. It can also refer to a set of circumstances or conditions we find ourselves in. Example: The situation (location) of the villa offers stunning views of the waterfall. / His addiction to heroin landed him in a miserable situation (condition that leads to misery). "Circumstance" is used to refer to conditions that can affect something else. Usually, these are negative conditions. Example: The explorers wanted to continue their expedition to the South Pole, but were forced to turn back due to unfavaourable circumstances. / If circumstances permit, we will tour the city. The "environment" is your surroundings, and its conditions. Your environment can be your room or your neighbourhood. You can have a pleasant environment or a noisy one. Hope this helps. Cheers, Lance

哦。。。这个问题难！期待看专业老师们的解释 （上这个网站后发现我的母语也要提高了!）