Task: Question Generation
Input (English): Background Paragraph: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature. 
Story: Two friends liked studying about the Earth's atmosphere. Vick studied more about the troposphere, while Frank studied more about the Greenhouse Effect.
Output (English): Which friend studied more about carbon dioxide?