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: Infertility affects one in ____ couples today.

A: five
****
Q: Some airports have ____ parallel runways.

A: two
****
Q: Wings are supposed to have evolved in at least ____ different groups as analogous structures.

A:
four
****