I humbly suggest that Beijing Mandarin pronunciation is not “standard” putonghua — otherwise, mostly of these sounds would end with a retroflex /r/.
I forget the details now, but “standard” putonghua has two variants, and each variant revolves around Jiangsu province (something like north and south?). Anyway, Beijing people think that they speak the “standard”. People educated in linguistics know better.
I forget the details now, but “standard” putonghua has two variants, and each variant revolves around Jiangsu province (something like north and south?). Anyway, Beijing people think that they speak the “standard”. People educated in linguistics know better.