The answer to this question is the Pyers
patches. The Pyers patches are lymphatic tissues found through
the small intestines that have an important role in the immune system. Pyers
patches are also known as the aggregated lymphoid nodules that monitors and
prevents growth of bacteria in the intestine that is harmful in the intestines.
The answer to this question is Condensation
There are no choices, I'll assume that the Nereus in the question refers to the underwater vehicle.
Facts about the Nereus
1) It is an HROV or <span>hybrid unmanned autonomous underwater vehicle. Operated underwater but its operator is in a remote location.
2) Built and operated by WHOI or </span>Woods Hole Oceanographic Institution<span>
3) Designed to explore the deepest surveyed point of the ocean worldwide named Challenger Deep.
4) Deepest dive was at 35,768 feet of the Mariana Trench last May 2009.
5) Was lost on May 10, 2014 after it imploded due to pressure in the Kermadec Trench</span>
...to go from mouth to anus varies from 24 to 72 hours.
A frog is an amphibian so it survive both on land and water
Hope this helps:)