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.

Carbon atoms are tetravalent, and therefore, can have ____ bonding pairs around each carbon atom.
four

Tall fescue produces the ____ diazaphenanthrene alkaloids, perlolidone and perloline.
two

Hydrocarbons have ____ ozone depleting and negligible global warming qualities.

zero