题目

Ali is from a Middle Eastern country. He now stays in the USA. He smokes a lot of cigarettes every day. He has smoked for nine years. Ali says, “ I tried to quit (放弃) smoking in my hometown, but it was impossible. My parents smoke. My brothers smoke. All my friends smoke. At parties and at meetings, almost all the men smoke. Here in the United States, not as many people smoke.  ____1____ ”       Many smokers are like Ali: they want to stop smoking.  ____2____  They know it can cause cancer and heart disease. But it is difficult for them to give up smoking because ciga若集合A＝{0,1,2，x}，B＝{1，x2}，A∪B＝A，则满足条件的实数x有(　　)A．1个 B．2个 C．3个 D．4个