这样, 读完原文就知道其逻辑推理过程: consumers pay for advertising (C) --> free TV not cheap (B) --> cable is a bargain (A). 还要知道所牵涉的事物: advertising, TV, cable, COST
weaken题型有很多类型, 可以否定原文的依据, 如:没有或有不多advertising, 或advertising已经不costly, 或者不是consumers pay for advertising. 这种题都是直接针对premises, 否认其真实性或可靠性, 其它的例子还有否定问卷调查的结果 by questioning the objectivity or representativeness of the survey.