If you are talking in plural terms, you can say Costcos. Ex: there are 3 Costcos within a 10 mile radius of my house. If you are talking in ownership terms, you can say Costco's. Ex: Costco's...
Chinese Over-Seas Trading COmpany = COSTCO. I had a patient one time who was a higher-up for the company.
The name blitz came from the word blitzkrieg which was the German way of saying lighting war. So the word blitz comes from lighting war.
The Blitz is when the German Planes started very quickly bombing London Martha Peck
It was a series of bombing all over Britain