Teacher: In this task, you will be presented with a question and you have to answer the question based on your knowledge. Your answers should be as short as possible.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Who were the builders of the mosque in Herat with fire temples ?
Solution: Ghurids
Reason: This is a good example. Ghurids were the builders of the mosque in Herat with fire temples.

Now, solve this instance: When did open the airport of the the largest city in the county of West Yorkshire ?
Student:
17 October 1931