【题目】These are the _________ ________(借书卡).
【答案】library cards
【解析】
句意“这些是借书卡。”借书卡library card,根据前面的are,可知用复数,library card的复数是library cards。故答案为library cards。

【题目】These are the _________ ________(借书卡).
【答案】library cards
【解析】
句意“这些是借书卡。”借书卡library card,根据前面的are,可知用复数,library card的复数是library cards。故答案为library cards。