Найдите все натуральные числа, которые больше по а + 7 и меньше а + 9, если: 1) а = 3; 2) а = 250; 3) а = 5000

First of all I want to tell you that my best friend's name is Irina and she is 15. She is the best person I have ever met. A few  words about her appearance. Her height is nearly 149 cm. But she'd like to be a bit taller. Well, she is not slim but she is not fat either.  Irina has a round face as everyone has, a bit long nose and big cheerful grey eyes. Her skin is a bit pale but she likes this fact, she doesn't like ruddy faces. She has no freckles as my friend Nina has. Her forehead is open. I think Irina has a charming smile.  Her hair isn't very short but it's not long either. It is straight and black. Iuina has rich hair. I think that she looks like her father. Irina is very active and creative, cheerful and curious. But the best thing is that she is reliable. We spend much time together. We go for a walk, we play tennis, watch TV, do things which we like. I love my friend.