Dear Mike, I am glad to receive your letter again. You wrote about Russian winter joy: skiing, skating, sledging. Frankly speaking, I have no idea of real snow. It never snows in my country! But we also had much fun during our Christmas holidays. My schoolmates and I travelled to Yellowstone National Park! I think it's a journey of my life. We enjoyed hiking, camping, boating, fishing, sightseeing... You know, Yellowstone became a national park in 1872 for its unique beauty and wildlife. There are many mountain lakes, canyons, rivers and mountain ranges in the park. We also had an opportunity to watch different species of mammals, birds and reptiles. By the way, took many photos of endangered animals in their natural habitat. Now I am thinking of taking part in one of the contests about wildlife held by the National Geographic Magazine. What about Russia, have you got any national GEOGRAPHIC parks in your country? What are they famous MAGAZINE for? How are endangered animals protected in Russia? I am looking forward to hearing from you as soon as possible. Best wishes, George THE NATIONAL

My address is Equality Street, 22.
I do not have much time to watch TV, but sometimes...
I often read books in the evening (s). 
I often go outside for a walk to get a breath of fresh air.
I'm an introverted person, so I not have many friends.
Если это formal writing, то не начинай предложение с but. Чтобы не делать предыдущее предложение слишком длинным, можешь написать 
However, they are very loyal to me and I am positive that they will never leave me alone. 
We spend much time together going...? Ты имеешь ввиду гулять? Тогда можно сказать We like to spend time together and hang out a lot after school. 
My father knows the answers for nearly all the questions he is being asked.
The older one is a mechanical engineer. He works in the North (ты имеешь ввиду на Севере?), so we don not see each other often. 
The younger one is fond of programming. (And he really likes it это одно и тоже, могу посоветовать написать о том, почему ему это нравиться)
I really miss my family. Напиши еще 1-2 предложения в конце как заключение. Например, о том как ты скучаешь по семье и думаешь полететь к ним на каникулы.

Я бы еще посоветовала не писать маленькие предложения когда ты можешь соединить их в одно.
I am a student in Aviation University. 
My father is a very experienced boiler room operator. 
My mother is a housewife with golden hands. 

1. I go to school every day.

2. My mother always cooks dinner for the whole family.

3. My brother  likes  to read a historical books.

4. She  prefers to drink coffee.

5. My father often helps me with my homework.

6. Do you like to listen to the music?

7. Do you help your little sister with her homework?

8. Does  he visit his grandmother in the summer?

9. Does your mother work at school?

10. Do they play football at school?

11.  My sister doesn't like to read at all.

12. My mother doesn't allow  me   to watch TV late at night.

13. We don't  go out with our friends very often.

14. My grandmother doesn't like my best friend.

15. I don't go to school on Sundays.

1I am speaking.
2You are joking.
3We are reading.
4I am sitting in front of you/
5She is telling me a story.
6The child is playing.
7The door is belling.
8The dog is running.
9I am thinking about you.
10You are preparing your homework.
11We are travelling all of the world.
12I’m going home
13She’s reading a book now
14We are going for a walk
15I am listening to music now