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: Human gestation is divided into three trimesters of ____ months each.

A: three
****
Q: R is an average of the color rendering ability of ____ or more specific colors.

A: eight
****
Q: Malignant tumors are more dangerous, and survival times can range from ____ months to several years.

A:
six
****