Fabrics. The properties of familiar materials are being changed by manufacturers who are adding nano-sized components to conventional materials to improve performance. For example, some clothing manufacturers are making water and stain repellent clothing using nano-sized whiskers in the fabric that cause water to bead up on the surface.
Reactivity of Materials. The properties of many conventional materials change when formed as nano-sized particles (nanoparticles). This is generally because nanoparticles have a greater surface area per weight than larger particles; they are therefore more reactive to some other molecules. For example, studies have shown that nanoparticles of iron can be effective in the cleanup of chemicals in groundwater because they react more efficiently to those chemicals than larger iron particles.
There are many different points of view about the nanotechnology. These differences start with the definition of nanotechnology. Some define it as any activity that involves manipulating materials between one nanometer and 100 nanometers. However, the original definition of nanotechnology involved building machines at the molecular scale and involves the
manipulation of materials on an atomic (about two-tenths of a nanometer) scale.
The debate continues with varying opinions about exactly what nanotechnology can achieve. Some researchers believe nanotechnology can be used to significantly extend the human lifespan or produce replicator-like devices that can create almost anything from simple raw materials. Others see nanotechnology only as a tool to help us do what we do now, but faster or better.
The third major area of debate concerns the timeframe of nanotechnology-related advances. Will nanotechnology have a significant impact on our day-to-day lives in a decade or two, or will many of these promised advances take considerably longer to become realities?
Finally, all the opinions about what nanotechnology can help us achieve echo with ethical challenges. If nanotechnology helps us to increase our lifespans or produce manufactured goods from inexpensive raw materials, what is the moral imperative about making such technology available to
all? Is there sufficient understanding or regulation of nanotech based materials to minimize possible harm to us or our environment?
参考答案：暂无
Passage 3：
题目：How Science was taught in school
题型：单选题4+填空题5+判断题5
新旧程度：旧题
文章大意：介绍学校传统的对science的教育受到批判，引出另外两种方法science on argumentation及science for explanation，并解释对比各自优劣
【写作】 TASK 1
The bar chart shows the percentage and exact time (weekly) males and females spent on house tasks in 2010 of a country. Summarise the information by selecting and reporting the main features and make comparisons where relevant.
(Word count： 199)
The bar chart illustrates how many females and males participate in house chores and how much time they spend in these tasks in the year of 2010 in a particular country.
It is quite evident that a larger proportion of females take part in the housework. Apart from house repair, in which more males allocated more time than females (14% versus 8%), the other categories all saw a higher female participation in the house tasks. Specifically speaking, there were 62% of females doing the cleaning, far outnumbering the males. The difference of figures was quite similar in cooking meals, where majority of females were engaged in this house task, compared with only less than a quarter of males.
In terms of the amount of time both genders spent, a substantial quadruple gap can be found in cooking meals and cleaning. Females averagely spent 82 and 42 minutes in cooking and cleaning, while their male counterparts only spent 21 and 10 minutes accordingly. Interestingly, the same quantity of time was spent in caring pets but men devote more time in house repair.
Overall, females are more involved in most of the household task, while house repair is more undertaken by males.
3月15日雅思考试机经真题回忆
