I recently called back the barber, Dino Ditizii, who has been working there since 1962.

最近我打电话给理发师蒂提兹（Dino Ditizii）， 他从1962年起就在那里工作。

The ambassador was called back to London by the prime minister.

大使被首相召回伦敦。

"Show yourself!" he called back.

“拿出证明！”他喊道。

"I did not know," he called back.

“我不知道，”他吼回去。

So, this is called back scattering.

这叫做背散射。