Final answer:
The three adverbs in the given sentence are 'soon,' 'too,' and 'uncomfortably,' each describing aspects of the action and quality of the jeans.
Step-by-step explanation:
In the sentence "I should purchase new jeans soon, because this pair is too short and uncomfortably tight," the three adverbs present are 'soon,' 'too,' and 'uncomfortably.' Adverbs describe verbs, adjectives, or other adverbs and typically answer questions such as how, when, where, how much, and how often. For example, 'soon' tells us when the jeans will be purchased, 'too' indicates the extent to which the jeans are short, and 'uncomfortably' describes the level of tightness experienced.