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

[Q]: The newest, outer layers of secondary xylem are called sapwood.
[A]: What are the newest, outer layers of secondary xylem called?


[Q]: In paragraph 2, they had been untouched for centuries does the phrase à¥ˆ€œfrozen in timeà¥ˆ€ suggest about the figures.
[A]: In paragraph 2, what does the phrase à¥ˆ€œfrozen in timeà¥ˆ€ suggest about the figures?


[Q]: Uranus is the least massive outer planet.
[A]:
Which is the least massive outer planet?