報IELTS問題

I have previously tested IELTS during the associate degree, but I only got 5.5. Now, I want to get 6 or above which can help me to enter university. Should I test IELTS again because the University may refer my IELTS result ? Will university refer UE result in A-level ( E grade ) or IELTS more ?
where can I find the past paper to practise more ? There are lots of IELTS courses outside, such as 現代, 遵理 . Are these courses useful for students or workers ? How about the tuition ?