Where the viruses are

The corona virus can survive for rather long periodsof time outside of the bodies of humans. Thisis one way the infection can spread. This article mentions some details. One detail I found interesting was that a virus can survive for different lengths of time, dependimg on what type of surface it is on. It survives for a longer time on steal than on cardboard. I wonder why, the article gives not even theories of the reason. I liked the article, anyway.