e6503375_009__Tanpa_Klasifikasi_Lugansk__3
[0] 38. [1] In order to prevent the environmental pollution in the place N, the artificial methods of sewage disposal, biological purification, chlorination and compulsory laboratory control are planned. Which one of the main artificial sewage disposal methods isn’t taken into account? [2] * Mechanical purification [4] Filtration [5] Irrigation [6] Areas of sewage disposal [3] 
Rechlorination
Krok 2009: Tanpa Klasifikasi Lugansk
3