【单选题】Without proper lessons, you could ____ a lot of bad habits when playing the piano.
【简答题】What are the two referencing skills?
【单选题】—What can I do for you? —I’d like to buy a present for my son, ______at a proper price but of great use.
【单选题】某企业2019年销售收入2 000万元,当年实际发生业务招待费50万元,该企业当年可在所得税税前列支的业务招待费金额是( )万元