D. the value of information in winning games
    （選項D的含義是：信息對于贏得比賽的價值。）
    葉碩/著 《愛上背單詞 高考關鍵詞》天津教育出版社
    Exercise：
    用上述所講單詞的適當形式填空。
    1. It’s difficult to keep _________ of all the new discoveries in genetics.
    2. New agreements will increase _________ between the two countries.
    3. I wouldn’t mind _________ jobs with her.
    4. The girls were playing _________ on their teacher.
    5. I’m not trying to _________ you—just answer the question.
    6. The company ran into _________ when it tried to expand too quickly.
    7. He often _________ the neighbors to take care of his dog when he lived there.
    8. His research has been of little practical _________.
    Key:
    1. track 2. trade 3. trading 4. tricks
    5. trick 6. trouble 7. troubled 8. value