Compréhension de l'oral
The listening axis: ear training on sounds and joins, then the B2 épreuve item types at natural speed.
You follow conversations at work all day, and then a colleague plays a France Inter flash and you lose the thread in nine seconds. Nothing about your French changed between those two moments. What changed is that spontaneous speech to you is slowed, repeated and repaired by the person speaking, while a radio bulletin is delivered at full speed to nobody in particular, with the joins closed and the words glued together. This domain is about that gap.
It closes it from underneath. The first move is perception, because the sounds you cannot yet tell apart are exactly the ones your brain has to guess at in real time, and guessing costs you the half-second the next clause needed — minimal pairs on the vowels and nasals that Russian does not distinguish, then the joins where French words stop having edges. The second is the exam itself: the DELF B2 compréhension de l'oral item types at authentic speed, main line and speaker stance before detail, then implication, register and irony. For an immersed learner this is usually the cheapest axis to bank marks on, which is why the diagnostic often puts it first — but the diagnostic decides, not the syllabus.