TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: The newest, outer layers of secondary xylem are called sapwood.

SOLUTION: What are the newest, outer layers of secondary xylem called?

PROBLEM: Carbon dioxide is an example of a material that easily undergoes sublimation.

SOLUTION: Carbon dioxide is an example of a material that easily undergoes what?

PROBLEM: Red is the color of mercury(ii) oxide.

SOLUTION:
What is the color of mercury(ii) oxide?