Identify the essential element missing from the following topic sentence. giving holiday gifts can be expensive! a. controlling idea b. limited topic c. concluding idea d. support for the main point

The appropriate response is “B. Limited topic.”

A topic sentence is, by definition, a controlling idea, so we can safely assume “A” is not what is missing because this sentence is a topic sentence.  Because a topic sentence is generally one of the first sentences in a paragraph, we know it is not missing a concluding idea because that would appear toward the end of a paragraph, so we know "C" is not the answer.  We can further determine that support for the main point is not missing from the topic sentence because support for the main point would appear following the topic sentence within the body of the paragraph, so we know "D" is not the answer.  What is missing, however, is a limited topic.  The way things currently stand with “Giving holiday gifts can be expensive!” is  a bit broad (almost too vague) which means there is potentially so much that can be covered that anything covered will be too superficial and underdeveloped.   By limiting the scope and narrowing the topic by, for instance, specifying the holiday, the types of presents, or the cost, one would be able to provide a well-developed and focused paragraph. 

different strategies reach different people based on their ability to understand the material. (from personal experience) when writing an argumentative essay write explaining the subject as though your audience never heard of it before and it is just being introduced, then explain why other people hate it also, afterward you would explain why that would be wrong. i hope that : )