In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

Q: Diarrhea is an illness that kills _ and one-half million children per year.

A: three
****
Q: Mature cysts have _ nuclei while the immature have two.

A: four
****
Q: Carbon always has _ bonds around it in an organic compound.

A:
four
****