题目

It's a small gas station that has snacks， drinks, cigarettes, and candies. The mid-aged man behind the counter knows his customers by name and what they normally want to buy. He treats children and adults with equal respect. When business is slow, he reads a science fiction behind the counter.One winter, three teenagers rushed in and grabbed(强夺) food off the shelves as fast as they could. Clearly, they were not about to pay for it. The man hit the panic button(应急按钮）, then went over the counter and locked the front door. The alarm bell rang. Certainly, theThree weren’t going aA为数轴上表示1的点，将点A沿数轴向左移动两个单位长度到点B，则点B所表示的数为