燃烧与我们的生活与社会的发展有着密切的联系。
(1)上图是燃烧条件示意图： 请根据初中所学知识，写出燃烧的三个条件： ① ② ③
(2)物质发生化学反应的同时，伴随着能量的变化，通常表现为 变化。人类通 过化学反应获得的能量，大多来自于化石燃料。石油是化石燃料之一，它属于 (填“纯净物”或“混合物”)。
(3)奥林匹克火炬(内部储有可燃物)是奥林匹克圣火的载体.
①采集奥林匹克圣火的唯一方式，是在奥林匹克的赫拉神庙前通过太阳光集中在凹面镜的中央， 引燃圣火。此过程中最关键的燃烧条件是 。
②北京奥运会火炬能在每小时 65 公里的强风和每小时 50 毫米雨量的情况下保持燃烧。但要实现 奥运圣火登顶珠峰，还需要解决最关键的燃烧条件是 。
(1)①可燃物 ② 氧气或空气 ③温度达到着火点(不要求顺序) (2)热量 混合物 (3)①温度达到着火点 ② 氧气或空气
Dogs are the best pets of humans. They come in all sizes. Some dogs are as small as a football, and others are as tall as a desk. Dogs’ fur (毛) is different, too. It can be long and soft, or smooth and hard. People don’t mind the kind of fur, because all dogs are good to hug.
请在字典中查一下这个词。
我喜欢甜食， 你知道的。
去年， 彼得在旅途中和许多人交了朋友。
我叫托尼· 史密斯， 史密斯是我的姓。
我们在课上回答问题时应该起立
Tea and coffee are two of the most popular drinks in the world. However, people usually like one more than the other. These drinks also have very different uses.
People in the office usually sit for most of the day when they work. But this is bad for a person’s health. When people sit for too long every day, they don’t move very much. So it is easy to start getting fat. Sitting too long is also bad for their work because it makes them want to sleep. When this happens, people may make more mistakes in their work or spend more time finishing their work. Companies need workers to be healthy, so how do they fix the problem?
