The other type doesn't use X-rays but instead a technology called millimeter-wave scanning.
另外一种不使用X射线，而是采用了一种叫做毫米波扫描的技术。
2
Light is an electromagnetic wave, with a longer wavelength than X-rays and ultraviolet, and a shorter wavelength than infra-red, microwaves and radio waves.
光是一种电磁波，其波长长于X光和紫外线，短于红外线、微波和无线电波。
3
“We still teach students analog X-ray techniques, but the emphasis is on digital radiography,” clinic director Herbert said. “This is the wave of the future.”