The pronoun it (line 13), underlined in the text, refers to 

Questões de assuntos semelhantes

•                  Newvaccine could fight nicotine addiction       Cigarette smokers who are having trouble quitting because of nicotine's...
• Our currency Australia was the first country in the world to have a complete system of bank...
• Turning Brown A four-year-old boy was eating an apple in the back seat of the car, when he asked, “Daddy, why is my apple turning brown?” ...
• Considerando-se o uso difundido do inglês na atualidade, o cartum remete à 
• On the Meaning of Being Chinese Ethnically speaking, I feel I am complicated to classify, but who isn’t, right? To...