1. What year did Esther Perel get married?
- Esther Perel got married in 1982.

2. Who was the 11th person to walk on the moon?
- The 11th person to walk on the moon was Charles Duke. He was part of the Apollo 16 mission, which landed on the moon in April 1972.

3. Which country has the most pyramids?
- The country with the most pyramids is Sudan. Although Egypt is famous for its pyramids, Sudan has a greater number of them. The pyramids in Sudan, particularly those in the region of Nubia, include the Pyramids of Meroë, which were constructed by the ancient Kingdom of Kush. In total, Sudan has over 200 pyramids, surpassing the number found in Egypt.

4. Do limes float or sink?
- Limes typically sink in water. This is because their density is generally higher than that of water. However, factors like the thickness of the lime's rind and the amount of air trapped within it can sometimes affect buoyancy, causing some limes to float. Generally speaking, limes are more likely to sink compared to lemons, which usually float due to their less dense structure.

5. What is the world's smallest mammal? 
- The world's smallest mammal by weight is the bumblebee bat (Craseonycteris thonglongyai), also known as Kitti's hog-nosed bat. It weighs around 1.5 to 2 grams (0.05 to 0.07 ounces) and has a wingspan of approximately 5.7 inches (14.5 centimeters). By length, the Etruscan shrew (Suncus etruscus) is considered the smallest, measuring about 1.4 to 2 inches (3.6 to 5.2 centimeters) long and weighing around 1.2 to 2.7 grams (0.04 to 0.09 ounces). Both species are remarkable for their tiny size and are among the smallest mammals on Earth.

6. What country had the 5th highest GDP in 2018?
- In 2018, the country with the 5th highest GDP was the United Kingdom. The top five countries by GDP in that year were:

United States
China
Japan
Germany
United Kingdom