本帖最后由 hannah2259 于 2009-3-25 22:16 编辑
补作业~~
按时做啦，不过上传比较遭罪~~晚上有实验~~
先补一些的~
let's look back in history to an earlier way of life.
at one time, children didn't have to learn any more than how to cope with their physical environment.
they have to learn to be careful around moving objects, to draw back when they got too close to something dangerous.
they didn't need a special school to learn these things other than the school of experiences, now was school necessary for them to learn how to survive,because their parents taught them all they needed to know about how to hunt and to till the soil.
But as the society became more complex, people depended more on others who were living far away.
So it became important for children to learn, to read and write.
when money was created, they need to learn to count and calculate.
children has to know these things in order to survive in this new expanded environment.
because such skills could not be learned simply from first-hand(to first term) experience, school became necessary, so that(the) children could be taught what we now call the three Rs: reading, writing and arithmetic.
OK. We’ve been talking about mechanics and then we still have a few minutes. Let me tell you about ancient Greek and what they thought about mechanics. They came up with a system that for them to describe different motions in different materials. more than 2000 years ago, Aristotle, the ancient Greek philosopher, assumed that all the matter on earth were made up of four substances, earth, water, air and fire. Under this system, earth is the densest, water is the next, air is less dense than water and fire is least dense of all. The heaviest object was made of earth and water, and lighter object contains significant amounts of fire or air. So Aristotle observe that different types of matter have different characteristics. He assumes this was because different types of matter were composed of different amounts of four primary substances. And Aristotle believes that the motions of objects could also be explained by the basic natures of f | 
发表于 2009-3-22 20:00:24
0
转发
签到领寄托币
GO
