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.

Airplanes still fly four to ____ times faster than zeppelins.
five

Swedes generally get ____ weeks of vacation each year and much of it is spent outdoors.
five

Mice become sexually mature in just a couple months and produce about ____ litters in one year.

eight