instruction:
In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
question:
Many comets have _ tails.
answer:
two


question:
Roundworms are fairly large worms that can grow to be _ or five inches long.
answer:
four


question:
Every oxygen links to one silica tetrahedron and _ ferromagnesian octahedra.
answer:

three