她在开始正式上课很久之前就已经学会了弹钢琴。

She had learned to play the piano ___long ___before she started formal lessons.

这张古董书桌在我继承它很久以前就一直在我们家里了。

This antique desk was in our house ___long ___before I inherited it.

在这种技术成为现实很久以前，科学家们就已经对其进行了理论推演。

Scientists had theorised about such technology ___long ___before it became a reality.