Given a scientific question, generate a correct answer to it.

[EX Q]: What is the basic structure that holds plants upright, allowing plants to get the sunlight and air they need?
[EX A]: stem

[EX Q]: What is the wavelength of light expressed in?
[EX A]: nanometers (nm)

[EX Q]: The planet neptune has strange dark spots that sometimes appear on its surface? what are these spots?
[EX A]:
storms