【Pinyin】Unit 13-Pronunciation Rule 6: Syllable-dividing mark markA-monthly/yearly members, Introductory Course
【Pinyin】Unit 12-Pronunciation Rule 5: Tone Sandhi of “不”“一”A-monthly/yearly members, Introductory Course
【Pinyin】Unit 9-Tips 4: Aspirated and Unaspirated InitialsA-monthly/yearly members, Introductory Course
【Pinyin】Unit 8-Tips 3: alveolar nasal “n” and velar nasal “ng”A-monthly/yearly members, Introductory Course