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

[EX Q]: Degradation is a result of _ simultaneous processes.
[EX A]: two

[EX Q]: Birds bitten by infected mosquitoes are infectious from _ to eight days.
[EX A]: four

[EX Q]: Reptiles also have scaly skin and a _ chambered heart.
[EX A]:
three