hear about
听说；得知
Did you hear about that pilot who had to jump out of his plane at twenty thousand feet?
你听说那个飞行员不得不在两千英尺高的空中从他的飞机里跳出来的事吗？
These days we often hear about "the classless society".
这些天我们经常听到有关“无阶级社会”的言论。
hear
听；听见
Do you hear someone holler?
你听到有人在喊叫吗?
Can you hear me?
你能听见我说话吗?
追问People often remember what they were doing when they heard the news of important events in history .这句话，和您举的例子不太一样吧？咋回事?
追答这里是听到的意思
当人们听到重大历史事件的新闻时，人们经常通常能记住自己正在做什么。
追问也可以翻译为：得知。用hear about？
追答hear about 后常接事件之类的名词，且需是（关于某人或某事）具体的事件，新闻，言论，事迹等。
这里只是说了新闻，没有提及具体是什么，所以只能用hear