務必 Simplified: 务必 On the HSK 7-9 vocabulary list, at CEFR level C2. wùbì ㄨˋ ㄅㄧˋ must to need to to be sure to Sources CC-CEDICT, CC BY-SA 4.0 pinyinjs, Apache-2.0 国际中文教育中文水平等级标准, 中华人民共和国教育部, MIT