例句與造句

1. Because these " cobalt machines " were expensive and required specialist support, they were often housed in " cobalt units ".
2. Medical linear particle accelerators, developed since the 1940s, began replacing x-ray and cobalt units in the 1980s and these older therapies are now declining.
3. It's difficult to find cobalt unit in a sentence. 用cobalt unit造句挺難的