现有的三维电视(至少，那些不需要戴三维眼镜的那种)通过在屏幕上现实交替图线。

Existing 3dtv (at least, the sort that does not need glasses) creates the separate images by showing them as alternating lines across the screen.

youdao

现在，科学家已经发明了一个小巧的装置，使得观看者能够在不需要特殊眼镜的情况下，看到三维的全息视频。

Now scientists have invented a gadget that allows viewers to watch three dimensional holographic videoes without the need for special glasses.

youdao

而后他们可以通过买卖每副150美元的观看这种三维效果的必备眼镜获得额外的数百美元的收益。

Then there were the hundreds of dollars more they could charge for all the spectacles (at $150 a pair) needed to view the three-dimensional effects.

youdao