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

[EX Q]: Figure skating is like flying, but it's also like climbing hundreds of stairs in _ minutes.
[EX A]: four

[EX Q]: Climatic regions Contrasts between the interior and the coasts produce _ main climatic regions.
[EX A]: six

[EX Q]: Natural tantalum contains _ isotopes.
[EX A]:
two