I had done a little working in the mineral department on trying to glass beads we'd imoorted from Czechoslovakia and had learned a little about their reflecting propreties. I'd been trying to make luminous house numbers - and maybe luminous signs as well - by developing luminous pigments. We looked around inside the company for skill in related areas. We drew on the expertise of our roofing people who knew something about exposure.
不好意思裡面有些單字打錯更正一下 imoorted→imported propreties→properties
- BayLv 51 0 年前最佳解答