"The boys write."
Translation:I ragazzi scrivono.
"Gli" is used as the definite article for plural masculine nouns that take "lo" or "l'" as the singular form. Generally, these are masculine nouns that begin with a vowel, a "z" or an "s" followed by a consonant.
l'albergo gli alberghi
lo spuntino gli spuntini
lo zio gli zii
more comprehensive listing of the rules can be found here: http://italian.about.com/od/grammar/a/italian-definite-articles.htm
The problem with this specific Question is the optons they offer for "write" in Italian are plural form of write. It said "The boys (plural) write. So it should have been scrivete- as this matched the examples when you click on "write" in the sentence, and is the plural form i6f write. Instead, the answer was scrivono- which is the answer to the singular form of write!! #TYPO
For "write/scrivere", the conjugations are:
I write = Io scrivo
You (sing.) write = Tu scrivi
He/She writes = Lui/Lei scrive
We write = Noi scriviamo
You (plural) write = Voi scrivete
They write = Loro scrivono
As I was typing that, I think i understand why you thought it should be "scrivete." However, "the boys" is a 3rd-person plural phrase (they) not 2nd-person plural (you). I hope that helps.