1 From the secondhand account, the reader gets more background information about what the Oregon Trail was. 2  From the firsthand account, the reader gets a better understanding why it was so dangerous.
Printers generally age more by the number of pages printed rather than by pure years. The rule of thumb has always been whatever the recommended volume is (for instance 5000 pages per month for a P3005) multiplied by say five or six years so about 300,000 pages would be the life expectancy of the printer.
Air conditioners and heat pumps last an average of 10 to 12 years, while furnaces have a life span of around 15 to 20 years. If your equipment is within those ranges, expect more repairs in the near future. Technology changes all the time. This is as true for your heating and cooling system as it is for your phone.