the greatest invention of the 20th century
It’s 6.55 on a Wednesday morning. The calf muscles are making the feet push on the pedals. The pedals are making the notched cog turn around, the cog is passing the movement onto the chain, which then is passing it on to the cogs in the rear wheel, making the wheel turn. The turning of the wheel is making the whole machine go. The machine is flesh and metal, bits of rubber and plastic. All perfectly fitted, synchronized, and at its place. It is quite unbelievable how all the parts know their job and perform it swiftly and willingly. In no time the machine gets at its destination. It’s 7.00 – in five minutes I managed to cover the distance of approximately 3 kilometers and not be late for the morning mass.
The bicycle is a relatively new invention. It is by far the most economical and environmentally-friendly mechanical mode of transport yet invented. Describe how the two-wheeled bicycle functions, and be sure to mention in your description the machine’s environmentally-friendly feature.
The two-wheeled bicycle is a very popular invention designed to shorten the time spent on travel. People use it for the purpose of traveling to work or school, or just spending free time with the family. However, there is a number of people who do not know how exactly this means of transport works.
Every bicycle is made up of such essential parts as the frame and wheels. The frame is designed to keep all the parts connected and prevent the bike from falling apart. The function of the wheels is to make the bike move on the ground. They consist of metal spokes and two wheel hubs, which keep the wheels rigid in their place. To work properly the bike also requires two pedals, the metal chain and notched cog. We push pedals in order to move the front notched cog, which by the metal chain transfers the motion to the rear notched cog. The latter function is to make the wheels move in a circular motion. The other essential parts of every bike are breaks. By pressing the brake levers we prevent the wheels from moving and thus we are able to stop the bicycle.
An important advantage of bicycles over other means of transport is that the former are thoroughly environmentally friendly. Unlike cars or buses, bikes do not emit any exhaust fumes. This and other factors make using a two-wheel-bicycles the best choice to spend free time with family or friends.
(247 words)