"It is fun to read a magazine."
Sticking を on the same tile as ざっし seems pretty stupid, looks like it cause a lot of confusion going by the comments.
So again, Duolingo, just let us input via keyboard as an alternative to these stupid tiles!
Have you seen Japanese children's books? That is how they parse things (particles stick to the nouns). I do not think it really should cause any confusion
It shouldn't cause confusion UNLESS you have never seen a Japanese children's book and I'm willing to bet that a significant amount of users here haven't therefore many of us are confused.
I wouldn't mind but it is inconsistent to every example I have seen thus far. I suppose it does catch out lazy readers, though.
We have to use の and は because they serve different grammatical roles.
の in this case is used to "noun-ify" a verb, in the same way we use the gerund (verb-ing) or the infinitive (to verb) in English.
On the other hand, は functions as it has always done, marking a noun as the topic/subject of the sentence, which is why both are necessary.
What word is "ざっしを" ? Why does DL Japanese sometimes smush things together on word tiles and sometimes separate good words?