这种老式的立体幻灯机通过两个投影仪创造出令人惊叹的三维效果。

This antique ___stereopticon creates amazing 3D effects by using two projectors.

19世纪的观众通过立体镜观看风景照片，感觉像真的到了那里一样。

In the 19th century, viewers used a ___stereopticon to look at landscape photos, feeling as if they were actually there.