Unlike watching TV, reading is a highly active process it requires attention as well as memory and imagination.
A. until
B. but
C. unless
D. for
网友回答
A. until
B. but
C. unless
(答案→)D. for
解析：检查考生对逻辑关联用语的掌握和运用能力。for引导的是并列分句。功能ⅰ）对前面的分句加以解释，ⅱ）说明推断的理由，for引导的句子只能后置。