Биосфера? дайте точное определение

Биосфера — оболочка Земли, заселена живыми организмами. Глобальная экосистема Земли.

1) 1. We dont speak French.
2. A lot of teenagers play computer games.
3. Do you study English every day?
4. He visits his grandmother twice a year.
2) 1. Mary went to school yesterday.
2. Did you go to the cinema on Sunday?
3. He didnt pass his exam last week.
4. She saw him two days ago.
3) 1. I going to call you. I promise.
2. Will you help me, please?
3. I think he wwont pass his driving test.
4. I have some plans for Monday. I going to visit my sister.
4) 1. He was a stuudent twenty years ago.
2. She will call you in a few minutes.
3. Did you buy milk yesterday?
 4. I get up at 7 am every morning.

I meet Ann last week. She is 25 yearss old. Ann is a teacher at High school. She has beautiful brown eyes and she is very tall and skinny.She has a husband and a lovely daughter. also Ann likes to play volleyball and basketball.  when i saw her at the very firs time she was moving to new place. she had a lot of stuff and I helped her. so we became friends anf good neighbours. one week ago she invited me to have a dinner with her family. we had fun. the dinner was really tasty, she made wonderful pancakes.