题目

When I met him, I had a lot of anger inside of me. I have lived my whole life in Spanish Harlem, but in my neighborhood, there are shoot-ups all the time. I know kids who have been shot or beaten up. I have friends who ended up in prison. I could have ended up that way, too, but Mr. Clark would not let that happen. Mr. Clark worked long hours, making sure I did my work. My grades rose. In fact the scores of our whole class rose. One day, he took our class to see The Phantom of the Opera, and it was the first time some kids had ever been out of Harlem. Before the show, he treated us to dinner a 下列关于一名普通中学生的数据，合理的是      A．质量约为500g                  B．重力约为50N    C．密度约为1×103g/cm3            D．体积约为0.05 m3