Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.

[Q]: Titanium is found in column ____ along with chemically similar zirconium, hafnium, and thorium.
[A]: four

[Q]: Cells contain ____ families of small organic molecules.
[A]: four

[Q]: Natural gadolinium is a mixture of ____ isotopes.
[A]:
seven