ЕТ - основни функционални характеристики

 https://docs.google.com/presentation/d/1xAEAxtjQdOd__ZK_w7fF7vKD4Omow7wj/edit?slide=id.p4#slide=id.p4

https://docs.google.com/presentation/d/1jFBK9jst_qIC_rNC5aOmDYL3B97wLw70/edit?slide=id.p4#slide=id.p4

https://docs.google.com/presentation/d/1T7icg4nJoRkCw9CLxuvvKHUqi7lxK0in/edit?slide=id.p1#slide=id.p1