Mensa IQ test

I have taken an online mensa IQ test up to 154, but there were 3 questions out of 39 that I had no idea of :-(.
I know the correct answers but I can't find out why! Maybe some of you can help me?

The correct answers are:
35: D
37: H
39: H

Maybe that's no longer an issue for you, but here's the logic behind it (it's pretty simple, just disguised well ;)), might still be useful for anyone, who's google-ing those answers:
35: the middle ones are the mirror, you switch accordingly
37: there's one blue and one red, they disappear when hitting a grey one and also change their color. Hence there's sometimes two reds or blues... :)
39: this one is again real simple, just disguised well, don't look at the symbols, look at the order of them! They move one spot every turn and change according to: c>t t>s s>c. Also, every line is separate.

Your explanation for answer 35 is very weak,maybe authors put it as correct answers.However,I have much stronger rule and my answer isn't here.Going through rows,we rotate left picture for 90 degrees in clockwise direction,if some of blue or red colour is on place of gray colour in middle,it changes colour.After that,we rotate picture for 90 in counter clockwise direction,like in the begging.So,the correct answer would be two blue squares with position like in G option from picture.

can you give me link of this test?