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

[EX Q]: Retinoic acid regulates oral epithelial differentiation by _ mechanisms.
[EX A]: two

[EX Q]: Plazas have _ accumulations of rubbish but are covered with even layers of mud bricks and plaster.
[EX A]: no

[EX Q]: Blood pressure is measured as _ values.
[EX A]:
two