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

[EX Q]: Flexible shapes are also shapes which have _ obvious way of being attacked.
[EX A]: no

[EX Q]: Essential oils have a non-toxic, residual effect of up to five months from just _ application.
[EX A]: one

[EX Q]: Plants grow through precisely spaced and sized holes in top and each of the _ sides.
[EX A]:
four