Text A

[1] Mammals, reptiles and amphibians are all vertebrates and share some similarities. A case in point is that they produce offspring through the union of a male sperm and a female egg. In spite of the similarity in the method of reproduction, these vertebrates have their distinctive features in other aspects. This essay will shed light on their similarities and defining features and differences.

[2] Mammals have live births and are delivered from the mother’s womb. They are warm-blooded animals, which means their body temperature does not change much according to the surroundings. Hair is a defining feature of mammals. It helps insulate mammals by trapping air. With a pair of lungs, mammals are able to inhale oxygen and exhale carbon dioxide.

[3] Unlike mammals, most reptiles are born from eggs. Another difference between reptiles and mammals is that most reptiles are cold-blooded, which means their body temperature varies depending on the surroundings. As reptiles do not maintain a constant body temperature like mammals do, they tend to live in warm places and stay in shade. In addition, reptiles do not have hair on their body. They have scales instead. However, both mammals and reptiles breathe with lungs.

[4] Amphibians are animals that can live on land and in water. Similar to reptiles, amphibians are cold-blooded and mostly born from eggs. In spite of these common features, one way to differentiate between the two is how their body is covered. Reptiles are covered in scales, whereas most amphibians have moist skin. Another distinctive feature of amphibians is their metamorphosis. Amphibians are born with a tail, breathe with gills and live in water when they are young. However, most of them will develop limbs and can live on land in their adult life. On the contrary, neither reptiles nor mammals undergo a dramatic change of form or shape from juvenile to adulthood. Another noteworthy difference is that in addition to breathing with lungs like mammals and reptiles, most adult amphibians can also breathe through skin.

[5] In short, despite all being vertebrates, mammals, reptiles and amphibians have some distinctive features that help to differentiate them from one another.

Text B

[1] The use of electric cars has been widely promoted around the globe in recent years as they are believed to be more environmentally friendly than petrol cars. Many drivers start to consider electric vehicles a viable alternative to petrol cars. The following essay seeks to compare electric cars and petrol cars in terms of convenience, impacts on the environment and the costs of ownership and maintenance to help drivers make informed decisions.

[2] Petrol cars may outcompete electric cars in terms of convenience. While drivers of petrol cars can simply fuel their vehicles in any petrol filling station when necessary, accurate estimation and advance planning on the time and locations of charging is required for drivers of electric cars to avoid interruptions to their journeys. As the charging process may take several hours, electric cars are also found to have a shorter operating range in comparison with petrol cars.

[3] Despite being less convenient and driver-friendly, electric cars outperform petrol cars in terms of environmental friendliness. Petrol-fuelled vehicles are one of the main culprits for air pollution as carbon dioxide, a greenhouse gas, is produced when fossil fuels are burnt. Electric vehicles, in contrast, have virtually no exhaust emissions. Although some may argue that air pollution is caused too when electricity is generated in power plants to charge electric cars, studies show that the greenhouse gas emitted can be as low as only one third of that from petrol cars. Therefore, electric cars are considered more environmentally-friendly than petrol cars overall.

[4] As for the costs of ownership and maintenance, petrol cars used to have a competitive advantage over electric cars when the technology required for producing the battery of electric cars was expensive. Nevertheless, with the advancement in technology, the production cost of electric cars has now been lowered. Further, governments worldwide are keen to provide incentives such as tax remission, grants and subsidies for owners of electric cars. Drivers of petrol cars, conversely, do not get to enjoy these benefits. All these help to close the gap and it is expected that in the near future, the costs of purchasing and maintaining electric cars may be similar to those of petrol cars.

[5] In conclusion, both electric cars and petrol cars have their own advantages and disadvantages. Drivers should weigh up the pros and cons when deciding which type is more suitable for them.