【单选题】The email we received yesterday is an inquiry ___________ discounts.
【单选题】The letter we received yesterday is an inquiry ____ discounts.
【单选题】We would like to inform you that we have received a large inquiry ____ 800 sets of refrigerators.
【单选题】The letter we received yesterday is an inquiry ___ discounts.
【单选题】The email we received yesterday is an inquiry ___________ discounts.
【单选题】张祜的《河满子》中“故国三千里,深宫二十年”中“故国”的意思是________