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

Ex Input:
Passage: A cross section of earthquake epicenters. The depth outlines the subducting plate. There are shallow, intermediate, and deep earthquakes. Answer: earthquake

Ex Output:
Subducting plate and epicenter are terms related to what phenomenon?

Ex Input:
Passage: Plate tectonic processes explain why we see many types of geological activity where we do. Stresses build up in some locations. These stresses may cause folding or faulting. Earthquakes strike along all three types of plate boundaries. The most damaging earthquakes are shallow focus. People in earthquake-prone regions must be aware of the potential damage from earthquakes. Seismologists have scales for measuring earthquake intensity and magnitude. Cities in earthquake zones must build safe structures. They also have guidelines for being safe in earthquakes. Earthquakes are often associated with volcanoes. Volcanoes erupt at all types of plate boundaries except transform. Volcanic eruptions can be quiet or explosive. Volcanoes have a variety of shapes. The shapes range from large shields, to classic peaks, to small cones. Supervolcano eruptions are rare but extremely deadly. Volcanic activity creates unique landforms. Hot springs and geysers result when water meets hot rock below ground. Some geological activity, both earthquakes and volcanic eruptions, is located away from plate boundaries. Answer: plate tectonics

Ex Output:
What causes a lot of geological activity on the earth?

Ex Input:
Passage: Lymphocytes ( Figure below ), a type of white blood cell, are the key cells of an immune response. There are trillions of lymphocytes in the human body. They make up about one quarter of all white blood cells. Usually, fewer than half of the body's lymphocytes are in the blood. The rest are in the lymph, lymph nodes, and lymph organs. Answer: lymphocytes

Ex Output:
What type of cells make up about one quarter of all white blood cells?