, , . : ●-3 . ● -2 . ● ( - 7 . . ● -1 .. ●-100 - 200 ● - 800 . ● - 4 . ● , 1\2 .. ● ● : 1. . 2. 7-8 , , . 3. , . 4. , , . 5. , . 6. 40 .