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

[EX Q]: Which atomic particle has a positive charge?
[EX A]: the proton

[EX Q]: Where do lancelets live?
[EX A]: shallow ocean water

[EX Q]: What the name of the disease where some of the alveoli of the lungs fill with fluid so they can no longer exchange gas?
[EX A]:
pneumonia