I honestly can't tell if you're joking or not...
Answer:
Language is Spanish. The answer would be:
"The Mackenzie is the longest river in Canada."
"tan bonito" does not make part of the sentence. The sentence is describing a girl, so instead it should say;
"tan bonita"
I dont think so. If ur citing from a book, newspaper.... everything should be written the same as what the book says. Hope it helps :)