What do you do to protect the environment?

I am trying not to throm garbage where it is not necessary.

Nina has been learning English for 2 years.
The birds have already flown to the South.
They have known him for many years.
Mike has forgotten to learn the poem.
The children have been watching cartoons for 2 hours.
The train has just come.
We haven’t had a holiday for 5 years.
She has been teaching at this school for twenty years.
David has been painting in his studio since 10 o’clock.
Mary and Sam have been collecting stamps for 3 years.
Their parents have been friends since their childhood.
Dave has been a student for 2 years.

Exercise 1. Choose the right tense form. Nina has been learning English for 2 years. The birds have already flown to the South. They have known him for many years.  (stative verb, thus no Continuous)Mike has forgotten to learn the poem. The children have been watching cartoons for 2 hours. The train has just come. We haven’t had a holiday for 5 years.  (same as 3)She has been teaching at this school for twenty years. David has been painting in his studio since 10 o’clock. Mary and Sam have been collecting stamps for 3 years. Exercise 2. Complete the sentences in Present Perfect or Present Perfect Continuous. I haven't seen him for ages. He has been doing his lessons since lunch. I haven't heard about him for a long time. I have been driving since I was 17. Jack has failed his driving test three times because he doesn't know how to park. I think he has made a lot of improvement. Alice hasn't passed her driving test because she doesn’t know the rules well. She has been worrying about this for two months. She has been studying the driver’s manual for hours every day. She hasn't taken another test yet.