I'm not a great Bible researcher. However, I have TWO NWT Bibles. One is the 1970 edition, and one is the 1984 edition. The 1984 edition was given to me by an ex-elder, and ALSO has "The reasoning from the scriptures" section, which is a book in itself, added onto the NWT Bible. If you are studying with j.w.'s, you will see that one of your teachers Bibles is much thicker than yours.That's because he has "The book of canned answers" ie: The Reasoning from the Scriptures".
Example.
Reasoning from the scriptures", page 137...IF SOMEONE SAYS ---"My minister said that Jehovah's Witnesses are the false prophets"
You might reply: "May I ask, did he show you anything in the bible that describes what we believe or do and that says people of that sort would be false prophets"? ....May I show you how the Bible describes false prophets? (Then use one or more points outlined on pages 132-136.)'
This is why it looks like they "know" their Bible.
Hubert