Definition: used to refer to events or experiences in the past Level: B2
在那之前，我们去哪里都坐公交车。
Before ___that, we used to take the bus everywhere.
那就是我学会游泳的那个夏天。
___That was the summer I learned how to swim.
那真是一次难忘的经历！
___That was such an unforgettable experience!
