Given a scientific passage and an answer, generate a question for the given answer.

Example Input: Passage: Earthquakes, essentially sound waves in Earth's crust, are an interesting example of how the speed of sound depends on the rigidity of the medium. Earthquakes have both longitudinal and transverse components, and these travel at different speeds. The bulk modulus of granite is greater than its shear modulus. For that reason, the speed of longitudinal or pressure waves (Pwaves) in earthquakes in granite is significantly higher than the speed of transverse or shear waves (S-waves). Both components of earthquakes travel slower in less rigid material, such as sediments. P-waves have speeds of 4 to 7 km/s, and S-waves correspondingly range in speed from 2 to 5 km/s, both being faster in more rigid material. The P-wave gets progressively farther ahead of the S-wave as they travel through Earth's crust. The time between the P- and S-waves is routinely used to determine the distance to their source, the epicenter of the earthquake. The speed of sound is affected by temperature in a given medium. For air at sea level, the speed of sound is given by. Answer: different speeds
Example Output: Earthquakes have both longitudinal and transverse components, and these travel at what?

Example Input: Passage: Cloning is the process of creating an exact genetic replica of an organism. The clone's DNA is exactly the same as the parent's DNA. Bacteria and other single-celled organisms have long been able to clone themselves through asexual reproduction. Plants can also reproduce asexually. In animals, however, cloning does not happen naturally. In 1997, that all changed when a sheep named Dolly was the first large mammal ever to be successfully cloned. Other animals can now also be cloned in a laboratory. Answer: cloning
Example Output: What is the process of creating an exact genetic replica of an organism called?

Example Input: Passage: Air temperature changes with altitude. This does not occur in the same way as pressure and density, which decrease with altitude. Changes in air temperature are not regular. A change in temperature with distance is called a temperature gradient . Answer: temperature gradient
Example Output:
A change in temperature with distance is called a what?