have been abroad 不用TO,什么时候不用TO,什么时候要TO

abroad,home,here,there……是常见的副词，所以前不加to。
e.g. go to school，go home，get to Beijing，get here……

abroad 像home用法一样在这里是副词。比较特殊 死记住就行了
要to的话跟地点名次 have been to beijing