题目

下列有关燃烧和灭火的说法不正确的是（） A . 可燃物只有在空气中才能燃烧 B . 通过降低温度可以灭火 C . 空气中混有可燃性气体，遇明火时可能发生爆炸 D . 木炭燃烧时，只会生成二氧化碳 答案：A,D — Do you still remember when we went to Nanjing?  — I can't remember now but ________sometime last summer? A. might it be     B. could it be     C. could it have been　 D. should it have been