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

[EX Q]: Comets are a bit like giant dirty ice-balls with diameters between _ and fifty kilometres.
[EX A]: five

[EX Q]: Mountain zebras can live up to _ days without drinking water.
[EX A]: three

[EX Q]: Water dissolves about one part in _ thousand parts, and receives a brown color.
[EX A]:
seven