There's a trick in the science passages! I usually get 80 - 90% correct on the science passages. What they do is that they give you a bunch of unnecessary details, that get you all immersed in it and you either skip things reading it (and miss the important parts), or spend too much time reading it.
What I do is quickly read. Like i'll read the passage, formulate what it is about, and then answer the questions. If they go on into detail about what the patterns on a butterfly's wings are, I tell myself, "I know where they talk about it, if it's THAT important, they'll ask a question about it, and i'll worry about it then."
Now, when I get to the questions, I can usually answer most of them without having to look back, BUT there's always detail questions where you want to input stuff you already know into the ideas of the passage. In those situations, I look back, make sure I find the ones that are wrong, and then answer the question.
I know you said looking back seems to waste a lot of time, and I would suggest trying to eliminate at least 2 of the answers before going back (if you can). Usually 2 of them are just super wrong and there's no way that would ever be right. Then you're left with the two that are somewhat similar, and it takes less time to find which one is wrong out of 2 vs. out of all 4.
