Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.

Q: Colostrum is bright yellowish thick milk secreted in the first ____ to six days after birth.

A: three
****
Q: Kayak paddles have ____ blades, canoe paddles have one.

A: two
****
Q: Natural uranium exists in the soil at a concentration of about ____ parts per million.

A:
four
****