помогите решить плиз...                                                                                                              1)2,4-диметил пентан . написать формулы всех изомеров.

2)При сгорании 15,6г. вещества,образуется 26,88г. СО2 и 10,8г. Н2О.Оприделите формулу ,если относительная плотность паров вещества по гелию=13.

3)уравнения реакций получения этена из а)этана б)хлорэтана в)1,2-дибромэтана г)этанола.

смоделировать  проблемы стран полупериферии в современном мире и наметить возможные пути решения

задание 2.7 вставьте артикли a/the , где они необходимы:

1.last week i met my friend. He was with young girl.This girl was student of uor Academy.

2.This is pencil. Pencil is red.

3.She is teacher. She is our teacher of English.

4.It is lake. This lake is deep. It's one of deepest lakes in world.

5.There are many flowers in your garden.Flowers in your garden are beautiful.

6.Did you write plat?Give me your plat,please.

7.Black Sea is in South of Russia.

8.This is Nick. He works as engineer. He is good engineer.

9.There are some schools in out street. Schools ere new.

10.Yuri Gagarin was first cosmonaut in world.

11.In summer sky is blue and sun shines brightly.

12.Petrovs are very friendly.

13.This is Ann's book. I don't like such book.

14.Winter begins in December.