Plastic
We use plastic wrap to protect our foods. We put our garbage in plastic bags or plastic cans. We sit on plastic chairs, play with plastic toys, drink from plastic cups, and wash our hair with shampoo from plastic bottles!
Plastic does not grow in nature. It is made by mixing certain things together. We call it a produced or manufactured material. Plastic was first made in the 1860s from plants, such as wood and cotton. That plastic was soft and burned easily.
The first modern plastics were made in the 1930s. Most clear plastic starts out as thick, black oil. That plastic coating inside a pan begins as natural gas.
Over the years, hundreds of different plastics have been developed. Some are hard and strong. Some are soft and bendable. Some are clear. Some are many-colored. There is a plastic for almost every need. Scientists continue to experiment with plastics. They hope to find even ways to use them!
2016届高考英语完型填空暑假检测题9
2016届高考英语暑假阅读理解检测题12
2016届高考英语暑假阅读理解检测题8
2016届高考英语语法填空和阅读理解复习题4
Happy birthday课件
Colour课件2
2016届高考英语阅读理解复习题3
2016届高考英语暑假阅读理解检测题11
How many pink balls课件
Colour课件9
2016届高考英语暑假阅读理解检测题1
2016届高考英语阅读理解复习题6
2016届高考英语阅读理解复习题2
2016届高考英语语法填空和阅读理解复习题10
2016届高考英语完型填空暑假检测题8
2016届高考英语语法填空和阅读理解复习题9
Fruit课件3
2016届高考英语完型填空暑假检测题4
2016届高考英语语法填空和阅读理解复习题6
2016届高考英语语法填空和阅读理解复习题3
Colour课件6
2016届高考英语阅读理解复习题11
2016届高考英语暑假阅读理解检测题6
Colour课件5
2016届高考英语阅读理解复习题1
2016届高考英语语法填空和阅读理解复习题1
Fruit课件1
2016届高考英语语法填空和阅读理解复习题11
Colour课件3
2016届高考英语阅读理解复习题10
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |