1. during和in都可以加上一段時間，即during/in + some time，意思是“在...期間”。
2. 兩者主要區別如下：
1）during強調在整個期間都存在或發生的狀態或動作；而in更多強調在期間某個時間所發生的動作。
如：I was in Beijing during the 1980s.
I went to Beijing many times in the 1980s.
2) 最關鍵的區別在于：如果后面加的并不是明顯的時間狀語詞語，而是能延續一段時間的活動名詞，如holiday,stay,visit,process等時，用during而不用in。
如： I felt happy during my stay in Beijing last year.

1中提到的我沒看懂

I was in Beijing in the 1980s

I went to Beijing many times during  1980s 這樣改了就不對了嗎？

老師覺得 during 和 in 怎么用呢