【Pinyin】Unit 13-Pronunciational rule 6: Syllable-diving markA-monthly/yearly members, Introductory Course
【Pinyin】Unit 12-Pronunciational rule 5: Tune Sandhi of “不”“一”A-monthly/yearly members, Introductory Course
【Pinyin】Unit 9-Differentiation 4: Aspirated and Unaspirated InitialsA-monthly/yearly members, Introductory Course