单选题 This book has been in the works so long that I have lost ______ of most of the sources found for me by the staff of the library.

【正确答案】 A

【答案解析】固定搭配题。lose track of意为“失去与…的联系；失去…的线索”。选项[B]trail意为“踪迹，痕迹，足迹”；选项[C]trace意为“痕迹，遗迹”；选项[D]clue意为“线索，助于解决问题或迷惑的某物”。所以正确答案为[A]。