Generate a question with a factual answer.
Generated: After a four-week period, who could refer a proposed measure to the Supreme Court?

Generate a question with a factual answer.
Generated: How many persons were necessary to operate an iron plow?

Generate a question with a factual answer.
Generated: When was the Japanese submarine offensive against Australia?

Generate a question with a factual answer.
Generated: When did the first whole genome duplication event occur?