Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[Q]: A change of season and less food usually cause certain animals to migrate.
[A]: Which two environmental changes usually cause certain animals to migrate?

[Q]: Present-day plants that have a complex vascular tissue system are called vasuluar plants.
[A]: Present-day plants that have a complex vascular tissue system are called what kind of plants?

[Q]: 50 s much time is required for a bicycle to travel a distance of 100 m at an average speed of 2 m/s.
[A]:
How much time is required for a bicycle to travel a distance of 100 m at an average speed of 2 m/s?