Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: Urea is made in the liver and excreted in urine.

Output: What is made in the liver and excreted in urine?


Input: Consider Input: Clear mucus is secreted before ejaculation to neutralize acidic urine remaining in the urethra.

Output: What is secreted before ejaculation to neutralize acidic urine remaining in the urethra?


Input: Consider Input: Many glasses eventually crystallize, rendering them brittle and this?


Output: Many glasses eventually crystallize, rendering them brittle and this?