This assignment requires that you explain, in your own words, which means do not simply copy from the text:

1. What is the difference between a primary and a secondary tax authority

2. How a practitioner would use each in a research assignment

This assignment requires that you explain in enough detail to show that you understand the response to the two issues.

This means that 2-3 sentences will NOT suffice. I hate to give a word length because the right length is as long as it takes to answer the question and not longer than that, but I would expect that 300-500 words will be required.