Answer: By adding closing sentence
Step-by-step explanation:
The introduction will be more effective if the writer would add a closing sentence. The main idea of closing sentences is to establish and restates the most important thing about the argumentative essay, to show what are the key and the main idea of that essay.
This introduction needs strength and stable information because these pieces of information are incomplete and they are left hanging. Because it is the argumentative essay it would be good to be clear about what the author is arguing and what is he trying to describe.