Ты поставила глаголы в неправильной форме. Исправляю.
1They are riding their bikes now. Are they riding their bikes now? Are they riding their bikes or horses now? What are they doing now? They are riding their bikes now, aren't they?
2 I am writing a letter now. I am writing a letter now, ain't I? Am I writing a letter now? Am I writing a letter or reading a book now? What am I doing now?
3We are having fun today. We are having fun today, aren't we? Are we having fun today? Are we having fun today or not? When are we having fun?
4 She is running in the park now. Is she running in the park now? Is she running in the park or playing tennis now? She is running in the park now, isn't she? Who is running in the park now?
5 I am swimming in the pool now. I am swimming in the pool now, ain't I? Am I swimming in the pool now? Am I swimming in the pool or fishing now? Where am I now?
1. Is Tasmania a small or large island? What are the wild forests are full of ? Is Tasmania very different from the other states? There are no deserts in Tasmania, aren't there?
2. Do the thousands of tourists visit Ayers Rock and a strange group of huge red stones called “the Olgas”? Where will you find the red heart of Australia? Are these places holy to the Aboriginals or to everyone? They believe that the land itself has life, don't they?
3. Is Sydney the best known place in New South Wales? What is the best known place in Australia? Are the Blue Mountains covered with forests of blue colored eucalyptus trees or fields of gold? When the sun shines, the air of the Blue Mountains is a real, beautiful blue, isn't it?
Do not worry, your interests will not take much time as long as you do not want to become a professional.
Of corse, you can engage in a hobby with a friend, but you should ask him if he loves to spend his free time in the same way as you. Most likely, he also has his hobby.