Does every GMAT Test Taker get a science passage? What's the key not to get lost in the wording?
I would suggest focusing on the opening and closing remarks of each paragraphs. When you see technical terms, decide whether they're simply examples or not. If they are, skip over them unless a question specifically asks about them. If they are crucial to the passage, just take 5-6 extra seconds to make sure you follow what's being said. Don't worry about forgetting things - just summarize each paragraph as you get through it, and have your overall outline ready at the end.
You only get the really hard ones with all the mumbo-jumbo when you're scoring high, so if you get a hard one, definitely don't panic - you're doing well.
You are definitely more likely to get a science passage than not to get one.