In this task, we ask you to write a question that asks about "event duration", based on a given sentence. The question will likely start with "How long". Your question should be answerable based on the common knowledge of how long certain events usually last. Don't create questions which have explicit mentions of answers in the text. Instead, it has to be implied from what is given. In other words, we want you to use "instinct" or "common sense". Note that the written questions are not required to have a single correct answer.

Input: Consider Input: Sentence: Natural Levees A flooding river often forms natural levees along its banks.

Output: How long does it take for a river to form?


Input: Consider Input: Sentence: Islam later emerged as the majority religion during the centuries of Ottoman rule, though a significant Christian minority remained.

Output: How long has a significant Christian minority remained?


Input: Consider Input: Sentence: Nibras and Quso delivered money to Khallad in Bangkok during Khallad's January 2000 trip to Kuala Lumpur and Bangkok.


Output: How long did it take them to get the money?


