Hi @SandraWang - yes, this is accurate. Having just taken the exam earlier this week, I can confirm that you only have one chance to answer every question, and that you cannot go back.
The reason for this is quite simple. Today's computer-adaptive testing is designed to rely on a common bank of questions, with each test basically being a compendium of unique questions for that sitting. Basically, the level of difficulty for each question that comes is progressively determined by how successful a test taker was with the previous band of difficulty. As such, you only have one chance for each question.
Having taken the CCSP recently (and thankfully having passed it), I can say that they give you plenty of time for the test. I had 240mins to answer 150 questions, and I was done in 2hrs 30min. I felt that there was ample time for the full test, even though some questions were so hard that I took 3 or even 4 minutes for them (maybe 20 or so of those really tough ones in total). For every question that's extremely tough, I think it's fair to say that there are many more that are more straightforward, in which you either know the basic concept or you don't - the more rigorous the study plan, the easier it will be to answer such straight concept Qs.
Hope that helps. Great question!
