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

[EX Q]: Armaments manufacturers use lithium to produce tritium in _ ways.
[EX A]: two

[EX Q]: Conserved residues make similar contacts in _ repressor-operator complexes.
[EX A]: two

[EX Q]: Life flows past the _ dimensions of the body like radio waves escaping from an electrical wire.
[EX A]:
three