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

Example Input: Passage: Relative dating determines which of two fossils is older or younger than the other but not their age in years. Relative dating is based on the positions of fossils in rock layers. Lower rock layers were laid down earlier, so they are assumed to contain older fossils. This is illustrated in Figure below . Answer: relative
Example Output: What type of dating determines which of two fossils is older or younger than the other but not their age in years?

Example Input: Passage: An addition reaction is a reaction in which an atom or molecule is added to an unsaturated molecule, making a single product . An addition reaction can be thought of as adding a molecule across the double or triple bond of an alkene or alkyne. Addition reactions are useful ways to introduce a new functional group into an organic molecule. Answer: an addition reaction
Example Output: What is a reaction in which an atom or molecule is added to an unsaturated molecule, making a single product?

Example Input: Passage: You know that ocean water is salty. How salty is it? What is the salinity of seawater? Average seawater is about 3.5% salt. The amount is different if there is a nearby source of freshwater. It is also different if there is a lot of evaporation in an area. How do you think these things affect seawater salinity? Seawater also contains other substances like sugars, acids, bases, and organic molecules. Answer: seawater
Example Output:
What water is about 3.5% salt?