during the 1990s
在 20 世纪 90 年代
There are extra flights to Colorado during the winter.
冬季有飞往科罗拉多的增开航班。
Please remain seated during the performance.
演出期间请不要站起来。
He was taken to the hospital during the night.
他在夜间被送到医院。
I only saw her once during my stay in Rome.
我在罗马逗留期间只见过她一次。
1.在...的期间;在...的时候
1.at one point within a period of time or a process
2.through all of a period of time