Lesson Details
Unit Nine: Things That Have Changed Our Life
Lesson 1: The Wheel
Key Words: circular, rotate, axis, propeller, turbine, mobility, journey (v), vehicle, invention, civilization
A. Look at the pictures and say which one is easier to move and why.
B. Read the text and answer the following questions.
Human beings have invented many important things so far. They have brought great civilization to the world through these inventions. Do you know which invention is the greatest? It is ‘the wheel’.
A wheel is a circular object. It can rotate around its axis and help easy movement of things across a surface.
The wheels are, in fact, everywhere. They are on our cars, trains, planes, wagons, and so on. Besides, they are on most factory and farm equipment. Fans, propellers, turbines are also other types of wheels.
So, the wheel is very important. We cannot imagine modern life without wheels. But do we know exactly who made the first wheel?
Questions
- What is a wheel?
- What can a wheel do?
- Where can you find wheels?
C. Fill in the blanks with appropriate words from the box. There are more words than necessary.
- difficult
- much
- circular
- important
- heavy
- first
Although the wheel is a very (a) _____ invention, the history of its origin is unknown. Experts guess that the first wheel was developed from a circular object. The early man observed that a huge piece of stone could be rolled easily if it was (b) _____ in shape. Similarly, a heavy tree-trunk is (c) _____ to carry, but it can be rolled away with less effort. Even, a gigantic tree-trunk can be moved easily using other small and round trunks as rollers under it. Thus, early man took advantage of rolling objects and developed the (d) _____ wheel. Apart from its mechanical advantage, a wheel’s mobility has contributed (e) _____ to the civilization.
D. Make as many correct sentences as you can using the substitution table. In the third column, there are more items than necessary.
| 1. | The wheel | a type of wheel. | |---|---|---| | 2. | A plain wheel | is rotated around its axis. | | 3. | It | has one of the simplest machines. | | 4. | A propeller | rotates around its axis. | | 5. | Wheels | are found on vehicles and machines. | | 6. | The wheel | helped in the rapid progress of civilization. |
E. Have you ever traveled by bus or car? Do you have any experience of what happens if one wheel falls flat. If yes, give a description of your experience. If no, imagine such a situation, and write a paragraph on it.
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