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: Most children start primary school at ____ years of age.

A: five
****
Q: Earth is the third planet from the Sun in our solar system, which includes ____ other planets.

A: seven
****
Q: Systems information is ____ dimensional because it varies with time.

A:
four
****