说明书 shuōmíngshū HSK6 manual Origin Definitions Defs Strokes Stroke Words Sentences Sents 化学品安全技术说明书 huàxuépǐn'ānquánjìshùshuōmíngshū MSDS material safety data sheet (MSDS)招股说明书 zhāogǔshuōmíngshū prospectus