【单选题】I delayed _______ your letter because I had been away for a week.
【单选题】I’m sorry I delayed_________ your letter because I have been quite busy these days.
【单选题】I delayed _______ your letter because I had been away for a week.
【单选题】I quickly answered your letter, for, if I delayed, you ______ I was not concerned about your difficulties.
【判断题】经营风险是企业在使用债务或考虑投资来源中是否有负债的前提下,企业未来收益的不确定性,它与资产的经营效率无关。( )