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

[EX Q]: Most broaches have _ series of teeth.
[EX A]: three

[EX Q]: Bilinear interpolation uses a weighted average of the _ nearest pixels.
[EX A]: four

[EX Q]: Muscat is divided into _ wilayats and is Oman's financial and trade centre.
[EX A]:
six