题目

Have you ever thought, “I wish I could take a year off and just travel around the world”? Well, three lucky American teenagers were able to do just that. The teens—two males and one female--got an all-expenses paid, yearlong hike to five continents. This trip didn’t include any five-star hotels or shopping funs. Eighteen-year-old Jamie Fiel from Keller, Texas, 17-year-old Arsen Ewing from Canyon, California, and 16-year-old Tyler Robinson from Lincoln, Massachusetts, didn’t expect fancy treatment. They signed up for the experience of a lifetime, which included hard work, often uncomf12．氧化性最弱的微粒是（　　）A．Cl2B．Na+C．Cu2+D．Mg2+