Translation:Quantum mechanics is very difficult but also very interesting.
In general I have found the pronunciation in this course very clear. But one thing I have found unexpected and difficult. This is the final sound of nặng-tone words like 'học' when they appear before words beginning in consonants. It seems that an additional nasal segment is added between the two words—in this case it sounds like an /m/ between 'học' and 'lượng'—which almost reminds me of the Cantonese word for 'not' being shoved in there! I would love to know a) whether all (Northern) speakers do this, and b) what the precise conditions are under which the phenomenon arises, because it has tripped me up many times on the audio questions.