Solar cookers, or ovens, have been used for centuries. A Swiss scientist made the first solar oven in 1767. Today, people are using solar cookers in many countries around the world. People use solar ovens to cook food and to heat drinking water to kill bacteria and other harmful organisms.

There are 3 kinds of solar ovens. The first is a box cooker. It is designed with a special wall that shines or reflects sunlight into the box. Heat gets trapped under a piece of glass or plastic covering the top of the cooker. A box oven is effective for slow cooking of large amounts of food.

The second kind of solar oven is a panel cooker. It includes several flat walls, or panels, that directly reflect the sun's light onto the food.

利用太阳能做饭 (1)
   全世界数以百万的人们每天生火烹煮食物。用于生火的木头通常很难找到，因此那些找不到木材的人就必须在煮食物所用的燃料上花费大笔的钱。然而，利用太阳能烹煮食物是一种更为简便的方法。

   人类使用太阳能炊具（或称太阳能灶）已有几个世纪了。一名瑞士科学家于1767年制成了第一台太阳能灶。如今，全世界许多国家的人们都在使用太阳能炊具。人们使用太阳能灶烹煮食物、加热饮用水，以杀死细菌和其它有害物。

   太阳能灶有三种，第一种是箱式太阳能炊具。在设计上，它有一层将太阳光反射进入箱内的特殊内壁，在炊具顶部覆盖着一层玻璃或塑料以收集热量。箱式太阳能灶用于慢慢烹煮大量食物非常有效。

   第二种太阳能灶是板式炊具。它由几块可以将太阳光直接反射到食物上平坦的似墙物（或板）组成。

As a result, people with Down syndrome are living longer. In 1983, they lived an average of just 25 years. Today the average life expectancy is 56. But that longer life has led to a sad discovery. People with Down syndrome may have an increased risk for Alzheimer's disease at an early age.

The National Down Syndrome Society says an estimated 25% of those 35 and older show signs of Alzheimer's. In the general population, this brain-wasting disease is usually not found until people are over the age of 65. It slowly destroys memory, thinking and reasoning skills.

什么是“唐氏综合症”？(2)

   患有唐氏综合症的人经常会有其他症状。这包括心脏、呼吸与听力方面的问题。但是许多这些症状是可以治疗的。

   结果，唐氏综合症患者如今活得更久了。在1983年，他们的平均寿命只是25年。而如今，平均期望寿命为56年。然而这更长的寿命引出了一个悲哀的发现。唐氏综合症患者在早年患上阿尔茨海默病的风险也许会增长。

   国家唐氏综合症协会表示，在那些35岁或更大年龄的人群里，估计有25%的人出现了阿尔茨海默病的症状。一般来说，这种脑萎缩疾病通常在患者65岁之前是不会发作的。该病缓慢的破坏人们的记忆、思维以及推理能力。

   唐氏综合症是最常见的引发智力缺陷的遗传因素。大多数唐氏综合症患者会轻度或是中度（智力）迟钝。许多人能够和其他学生一起参加日常的学习。以后，作为成年人，许多人有工作并独立生活。在美国，约有35万人患有唐氏综合症。

Deep inside each cell in our body is all the genetic information needed for life. Human genes are normally organized along 46 chromosomes -- 23 from each parent. But as a result of a mistake in cell division, some people have 3 copies of the 21st chromosome. There are supposed to be just 2.

About 1 in every 700 babies has this extra copy. The name for this condition is Down syndrome. A British doctor named John Langdon Down first described it in the 1860s.

Republican vice presidential candidate Sarah Palin has a son who was born in April with Down syndrome. The Alaska governor and her husband also have 4 other children who do not have it.

Many babies with Down syndrome have low muscle tone, so they need extra support when they are held. Their heads are smaller than average and they can have unusually shaped ears. Also, their eyes often angle upward.

什么是“唐氏综合症”？(1)

     我们身体的每一个细胞中都有着我们生命所需的遗传信息。通常，人类的基因是由46条染色体组成的，从父母那里各遗传到23条。但是由于细胞的分裂时发生错误，有些人的第21条染色体有三条，而一般的人只有2条。

    大约每700个婴儿就有一个孩子携带这条多余的染色体。有多余的染色体。这种症状就是唐氏综合症。英国医生约翰•朗顿•唐(John Langdon Down)在19世纪60年代首次对此作了描述。

    共和党副总统的候选人Sarah Palin在4月出生的儿子就患有这种唐氏综合症。这位阿拉斯加的州长和她的丈夫还有四个孩子，但未患此种疾病。

    许多患有唐氏综合症的新生儿肌肉张力低下，因此，在他们保持姿势时就需要额外的支撑。他们的头比一般的新生儿要小，耳朵的形状也与众不同。而且，他们的眼角斜向外上。