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]: Luminosity decreases by almost four orders of magnitude in approximately ____ million years.
[A]: five


[Q]: Lancelets display all ____ of the vertebrate characteristics throughout their lives.
[A]: four


[Q]: Children are usually able to brush and floss by themselves at six or ____ years of age.
[A]:
seven