Twenty years ago – on June 4, 1989 – three events shaped a fateful year. Which do you remember most vividly, and which most changed the world?
给历史发烧友们出道题。20年前的1989年6月4日，有三件大事书写了那一年的历史。你对其中哪一件印象最深刻，又是哪一件最显著地改变了世界？