这个展览使用了全息投影技术，让观众仿佛置身于外太空。

The exhibition used a ___holographic display to make visitors feel like they were in outer space.

这封信很有价值，因为它是那位著名诗人亲笔书写的真迹。

The letter is valuable as it's a ___holographic note written by the famous poet himself.