Those tests are incredibly hard to study for since they cover so much material.
I think the best approach is to brush up on a few of the basics like ohms law, and some of the simple math formula's used in HVAC, then go give it a shot. Just make strong mental notes of the subjects that leave you baffled (and there likely will be several questions that will make you scratch your head).
Also, when taking the tests be sure to read the question very well, don't skip through it. They love to do the test tricks... using "every" "all the time" "and" etc to affect which answer you pick.
One other suggestion I have is to go through the test, answer the questions you know the answers to. Then make a 2nd pass, good odds are some of the questions you skipped the 1st time will come to you this time around. And on your final pass... do your best to make an educated guess... like looking at the clock and seeing which quarter the second hand is in, and choosing A B C or D based on that lol
"If you call that hard work, a koalas life would look heroic."
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