Hi
I strongly believe that the YES/NO/NG type question is very subjective nature , it has been extracted from part of article,book,....
and someone else who is IELTS's designer had a understanding from that and therefore ask some questions based on his/her perception
Why his perception must be correct
xD
I think by far the most difficult part is Y/N/NG merely because of this reason, You(candidate) should realize other's understanding and sometimes it would not easy.
in each of my test I really find some alternative answer and this has been made me disappointed
I strongly believe that the YES/NO/NG type question is very subjective nature , it has been extracted from part of article,book,....
and someone else who is IELTS's designer had a understanding from that and therefore ask some questions based on his/her perception
Why his perception must be correct

I think by far the most difficult part is Y/N/NG merely because of this reason, You(candidate) should realize other's understanding and sometimes it would not easy.
in each of my test I really find some alternative answer and this has been made me disappointed