Interactions in EcosystemsThere are many factors that can affect an ecosystem: water, sunlight, soil, pollution, and fire are just a few. Water is, in many cases, the main factor that can affect an ecosystem. When an ecosystem is very dry, only a small number of species of plants and animals can survive. A rain forest has so much water that many animals and plants can live there. Drought can cause plants to die. When plants die, consumers that need them for food will also die. Another resource that can affect an ecosystem is sunlight. Some plants, such as cacti, grow where there is little water but a lot of sunlight. Without sunlight, plants cannot produce food and will die. If plants die, consumers that depend on them for food will also die. Air pollution can come from forest fires or volcanoes, but most of it comes from cars and factories. Gasoline, coal, and other fuels can pollute the air as they burn. Burning fuels release compounds of sulfur and nitrogen into the air. These mix with water and fall to Earth as acid rain. Acid rain can harm lakes, forests, and soil. It can also greatly harm many plants and animals. For example, the chemicals in acid rain can harm leaves. As a result, the plant cannot get the carbon dioxide it needs to make food. Pollution from cars, homes, and factories may mix with water in the air to produce smog. Smog is like a gray cloud in the air. It can be harmful to people because it makes air hard to breathe and can damage our lungs. Large fires can also affect an ecosystem. Fires can have natural causes like lightening. However, the majority of fires are caused by people who are not careful in handling fire. Fires can destroy life on vast stretches of land, especially forests.全文翻译：全文翻译： 1. There are many factors that can affect an ecosystem: water, sunlight, soil, pollution, and fire are just a few. 有很多因素可以影响生态系统，水，阳光，泥土，污染，火灾只是其中的一 小部分。 2. Water is, in many cases, the main factor that can affect an ecosystem. When an ecosystem is very dry, only a small number of species of plants and animals can survive. 在很多情况下，水是影响生态系统的主要因素。当周围环境十分干燥时，仅 仅只有一小部分植物与动物能够存活下来。 3. A rain forest has so much water that many animals and plants can live there. Drought can cause plants to die. When plants die, consumers that need them for food will also die. Another resource that can affect an ecosystem is sunlight. Some plants, such as cacti, grow where there is little water but a lot of sunlight. Without sunlight, plants cannot produce food and will die. If plants die, consumers that depend on them for food will also die. 许多动植物能够在雨林中存活下来，因为那里水分充足。干燥的环境会使植 物死亡，而当植物渐渐死亡，以这些植物为食物生存的消费者也濒临死亡。另 一个会影响生态系统平衡的因素是阳光，比如，像仙人掌这种植物的生活环境 只需要一点点水分，但大量的阳光是必不可少的。没有阳光的照射，植物无法 进行光合作用产生食物也同样会死亡。如果植物死亡了，那些吃这些植物为生 的生物也将会死亡。 4. Air pollution can come from forest fires or volcanoes, but most of it comes from cars and factories. Gasoline, coal, and other fuels can pollute the air as they burn. Burning fuels release compounds of sulfur and nitrogen into the air. These mix with water and fall to Earth as acid rain. Acid rain can harm lakes, forests, and soil. It can also greatly harm many plants and animals. For example, the chemicals in acid rain can harm leaves. As a result, the plant cannot get the carbon dioxide it needs to make food. 尽管森林火灾和火山爆发会导致空气污染，但其罪魁祸首还是汽车所排放的 尾气和工厂废气。汽油，煤，以及其他燃料在燃烧的时候也会污染空气，因为 在燃烧的过程中，燃料会向空气释放硫磺和氮气的混合物，这种化学物质会与 水再混合，并形成酸雨落入泥土。酸雨不仅对湖，森林和泥土有害，同时也严 重损害了大量动植物，就比如酸雨中的化学物质会损害树叶，其结果便是使得 植物无法获得它所需要的二氧化碳来制造养分。 5. Pollution from cars, homes, and factories may mix with water in the air to produce smog. Smog is like a gray cloud in the air. It can be harmful to people because it makes air hard to breathe and can damage our lungs. 从汽车中，家里，以及工厂中所排放出的废气可能会与空气中的水混合，进 而形成烟雾。烟雾就像空中一朵灰色的云，有所不同的是，这朵灰色的“云” 对人体有害，它污染了我们所吸入的空气，而有害于我们的肺。 6. Large fires can also affect an ecosystem. Fires can have natural causes like lightening. However, the majority of fires are caused by people who are not careful in handling fire. Fires can destroy life on vast stretches of land, especially forests. 大型火灾一样会破坏生态系统。类似闪电等的一些自然因素，会引起火灾， 然而大多数火灾是由于人们使用火时的不小心，火灾会毁了一大片土地以及生 活在上面的生命，尤其是森林。Interactions in EcosystemsThere are many factors that can _1_ an ecosystem: water, sunlight, soil, pollution, and fire are just a few. Water is, in many cases, the main factor that can affect an ecosystem. When an ecosystem is very dry, only a small number of _2_ of plants and animals can survive. A rain forest has so much water that many animals and plants can live there. Drought can cause plants _3_. When plants die, consumers that need them for food will also die. Another resource that can affect an ecosystem is sunlight. Some plants, such as cacti, grow _4_ is little water but a lot of sunlight. Without sunlight, plants cannot produce food and will die. If plants die, consumers that depend on them for food will also die. Air pollution can come from forest fires or volcanoes, _5_ most of it co