1. I've known him all my life, haven’t` I? – разделительный
Have I known him all my life? – Общий
Have I known him or her all my life? -альтернативный
Who has known him all my life? – К подлежащему
How long have I known him? – Специальный
2. There is a bridge over the river, isn`t there? – разделительный
Is there a bridge over the river? – Общий
Is there a bridge over the river or lake? альтернативный
What is over the river? К подлежащему
Where is there a bridge? – Специальный
3. I would like a cup of tea, wouldn`t I? – разделительный
Would I like a cup of tea? – Общий
Would I like a cup of tea or coffee? альтернативный
Who would like a cup of tea? К подлежащему
What would I like? – Специальный
4. Yesterday I spoke to my sister, didn`t I? – разделительный
Did I speak to my sister yesterday? – Общий
Did I speak to my sister or brother yesterday? альтернативный
Who spoke to my sister yesterday? К подлежащему
When did I speak to my sister? – Специальный
However, all is not so bad. We have thousands of organizations and even corporations that are trying to popularize alternative energy sources. And their work is noticeable. Electric automobiles are becoming more and more popular. Plants and factories are using modern technologies to reduce emissions. Somebody could say "Hey, you're too optimistic and we all are going to the abyss." But I'm not an optimist, I just see all the improvements last years that are believed to change the situation all over the world.
You and I have only to help in this by promoting new harmless technologies. Maybe they aren't too profitable right now, but someday they will replace old and harmful one.
I believe that our future world will not be a big trash. It will be a pretty place with beautiful nature and complementary synthesis of nature and technology.