To be thus is nothing is when Macbeth is talking about not being as safe as king.
The answer is about being the king.
The excretory system is a close partner with both the circulatory and endocrine system. The circulatory system connection is obvious. Blood that circulates through the body passes through one of the two kidneys. Urea, uric acid, and water are removed from the blood and most of the water is put back into the system.
Is there more to this question ??
A bookworm is probably someone who reads a lot of books.