The end of the year, the company has a total of 11 water treatment, but the company was unable to identify the addresses of individual waste water treatment machines, therefore we have random observations that project a.
End of the year, the Company had a total of 11 water treatment machine, but the company can not determine the address of each water treatment, so we can observe the project then.
The company has all 11 machines, water treatment machines But the company cannot enter the address of the air purification machine, so we each random observer program AE