The sentece that logically fits right before sentence 3 is "<em>While some programs focus on assisting those who are affected of bullying, others concentrate on changing the behaviour of the bullies</em>".
The reason behind this choice is that the sentence 2 introduces the idea of school programs to help stop bullying and this idea is developed in the sentence that has to be added before 3.
As regards the last question, your answer based should be based on your own experience. In case you have witnessed a bullying incident in school, your answer has to be affirmative. Otherwise, it should be negative.
