Here, the holy cow represents the quality of the input whose outcome is juicy hamburgers. Going by this association, you can say that the holy cow represents a sound value system that produces the best hamburgers as commendable results. This can be exemplified by the economic equation where business tycoons who worship their work have done wonders for their shareholders.
Or you can reflect on the word holy. In the social context, Indians consider the cow to be holy; hence it is a sin in our culture to slaughter the holy animal to make hamburgers. Hence, holy cows are not worshipped and fattened to produce the best hamburgers at least in our country. Another way of looking at it would be to say that the holy cow might fail to produce the best hamburgers because of mad cow disease which prevents it from being put to good use. This can mean that even the best inputs might fail to produce desired results.
The above example also throws up another technique of effectively handling abstract topic. You can connect the topic creatively to current affairs or other subjects of your interest-sports, economics, politics, entertainment, humor. this will help you feel make an impact by making a confident start of the GD, While practicing for abstract GDs you can pick a topic and make at least two points for every subject you can connect it to.
Abstract topic can be discussed by exploring the metaphoric meanings then can be attributed to the keywords.
For instance,
Life is a chair
A chair can be having different meanings to it with respect to life. You can use it to discuss the constant political struggle to acquire the best chair or the significance of one's position in the society or a company depicted by the chair one occupies. A chair can trace the growth of a person from childhood- baby chair -to old age-a rocking chair. You can use these meanings to talk of different ways in which life can be like a chair.
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