Personally I think it is a poorly designed course
Bingo. The advanced textbook--I can't speak for the others--is a disaster.
Once I was asking my co-worker about one question I absolutely could not figure out.
Me: Both "a" and "c" look like they could both be correct.
A-san: They are both correct, but the answer is "c."
Me: ? If the answers are both correct, why is it c?
A-san: C sounds more natural. A native speaker of Japanese can hear the difference, like in English how you COULD say "I'm going for a drive in my vehicle," but it sounds weird and you wouldn't say it. You'd say, "I'm going for a drive in my car."
Me: But...but...the book never explains that. And even if it did, how would I know? I'm not a native speaker.
The book expects you to keep up with things you simply can't, gives no explanations for anything, and sometimes gives examples with different verb forms or several possible meanings without explaining what's different about them. I suggest not taking it, or taking it only if you have a tutor/teacher to explain things to you.
"Am I missing something?" asked Annabelle.
"I think you're missing a lot of things," Jimmy replied.
-From "Demon of Renaissance Drive"