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

Q: Transitional milk is secreted between about four days and _ days postpartum.

A: ten
****
Q: Diatoms are in _ shells and make the water brown.

A: two
****
Q: Young cows are usually worst-affected, because they have _ previous exposure and immunity.

A:
no
****