GED考试是美国高中同等学历考试，主要针对没有完成高中学业的人设置的，通过GED考试就能证明自己拥有高中学历。GED考试主要考察科学、数学，社会学科、英语(阅读和写作)等内容，每部分分数在100到200分之间，最低及格分数为145分。
GED科学考试主要评估学生理解、解释和应用科学信息的能力，考试时长90分钟，共34个问题，题型包括多项选择、下拉菜单、拖放题、填空题、热点题、简答题等等。问题基于阅读文章、图表、表格、图形，地图等。
备考GED科学考试，做习题是非常有帮助的，可以很明确的了解出题的规律，积累遇到的各种问题的经验。下面留求艺留学也为大家总结了GED科学考试内容及真题答案讲解，来看看这些题目你都会做吗？
1、生命科学(40%，大约40个问题中的16个)
生命科学包括:
人体与健康 ；
生命和能量(如食物和热量、光合作用) ；
生态系统中的能量流动(如食物链、捕食者和猎物) ；
生命的组织(如细胞、器官、身体系统) ；
遗传的分子基础(如DNA和遗传学) ；
演变；
题目：
A scientist collected the following data about the trees growing in a forest over 10 years.
Which is the best conclusion the scientist can make about the change in the forest?
The number of pine and fir trees doubled in ten years.
The forest’s climate is changing to become colder, so that oak trees do not grow as well.
The number of evergreen trees increased, while the number of oak trees decreased.
The forest is getting more rainfall, which is causing the overall amount of trees to increase.
答案：The number of evergreen trees increased, while the number of oak trees decreased.
2、物理科学(40%，约40题中的16题)
GED考试中的物理科学可以涵盖以下任何主题:
热量、温度以及热量的流动和传递；
产生或利用热量的化学反应和生命过程；
能量的类型和能量的转化；
能源，如太阳或燃料；
波浪和光；
速度、速率、加速度、动量和碰撞；
力和重力；
物质的结构，包括原子和分子；
物质的属性，如状态(液体、气体)和密度；
化学和化学方程式；
溶液，例如将盐溶解在水中；
题目：
In a chemical equation, there should be the same number of atoms on each side. Choose the correct answer to complete the equation, which shows that combining methane plus oxygen creates carbon dioxide and water. CH4 + ________O2 → CO2 + 2H2O
Choices：2，3，4，5
答案：2
3、地球和空间科学(20%，大约40个问题中的16个)
地球和空间科学问题可包括以下任何主题的信息:
地球上生物和非生物之间的相互作用，如碳循环、水循环或化石燃料；
暴风雨或地震等自然灾害；
水、燃料、土地和食物等自然资源；
大气和海洋；
地球的系统，如侵蚀 地球的结构，如地核、地幔和地壳 宇宙、星系、恒星和太阳系；
太阳、行星、彗星、小行星和卫星，包括地球和太阳系的运动；
地球的年龄，包括化石、地貌和测定地球岩石的年代；
题目：
What Is Mercury Like? The surface of Mercury looks much like Earth's moon, and it is marked with many impact craters. Mercury has almost no atmosphere. Because it is so close to the sun, it can be extremely hot. For example, on its sunny side, Mercury can reach a scorching 800 degrees Fahrenheit. (However, Mercury is not the hottest planet in the solar system—Venus is the hottest planet.) On its dark side, Mercury gets extremely cold because it has almost no atmosphere to hold in heat and keep the surface warm. The temperature can drop down to minus 300 degrees Fahrenheit. Sunlight never reaches into the bottoms of some craters near Mercury's poles, which could mean that ice may be inside those craters, where there would be constant freezing temperatures. How Has NASA Studied Mercury? Because it is so close to the sun, Mercury is difficult to study from Earth. No humans have ever traveled to Mercury, but the first robotic spacecraft to visit Mercury was Mariner 10. It flew by Mercury in 1974 and 1975. Mariner 10 was able to take pictures of less than half of Mercury's surface. Following Mariner 10, no spacecraft visited Mercury for more than 30 years. Then NASA's MESSENGER flew by Mercury in 2008 and 2009. On March 17, 2011, it began its orbit of Mercury. MESSENGER will map Mercury by taking pictures of the planet's surface, including some areas that have not been seen before. It will also collect data on the composition of the surface rocks, and measure the heights of mountains and depths of craters and valleys. Some data collected by MESSENGER will help scientists to understand what the inside of Mercury is like. MESSENGER will let people learn more about Mercury than they ever have before. Source: Adapted from “What Is the Planet Mercury?” by David Hitt, March 30, 2011.
based on the article, which piece of information do scientists NOT know about Mercury?
Whether asteroids or other objects from space have crashed into Mercury’s surface；
The effects of Mercury’s atmosphere on its temperature；
The structure of the center of Mercury；
The temperature range on the surface of Mercury；
答案：The structure of the center of Mercury.
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