Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-171

The human eye is (35) __________ incredible biological camera, more complex than any technology. It allows us to see our world in vibrant detail. The process begins when light reflects off objects—like a book or a tree—and travels towards our eyes. This journey of light is the first essential step in the process of vision.

When light enters the eye, it first passes through the pupil, the central black dot which controls the amount of light getting in. After the pupil, the light reaches the lens. The lens then (36) __________ this light, bending it to create a sharp image, much like a camera lens focusing on a subject before taking a picture.

This focused image is projected onto the retina, a layer of special cells at the back of the eye. Interestingly, the image that forms on the retina is actually upside down. (37) __________, the brain has an important job to do. It is up to the brain (38) __________ this upside-down information and turn it the right way up so it makes sense.

The retina converts light patterns into electrical signals, sending them along the optic nerve to the brain. The brain receives these signals and must then (39) __________ this complex information. A scientist once explained that the brain (40) __________ the real organ of sight, not the eye. This interpretation is so fast that we are unaware the image was ever inverted.

Vision is truly a partnership. If our brains (41) __________ this information correctly, we would see a confusing, upside-down world. The eye gathers the light, but the brain creates our perception. Understanding this may seem difficult, but it's not rocket (42) __________.

Across the bustling cities of Vietnam, a new sound is becoming more common: the quiet hum of electric motorbikes. Increasingly popular among students and adults alike, these vehicles are promoted by companies like VinFast as a modern, environmentally friendly alternative to the traditional petrol-powered motorbike. They promise cleaner air and a greener future for urban transportation. But as their numbers grow, a critical question arises: are electric motorbikes truly the perfect environmental solution they appear to be?

The most celebrated advantage of electric motorbikes is their lack of tailpipe emissions. Unlike their gasoline counterparts, they do not release harmful pollutants such as carbon monoxide and nitrogen oxides directly onto city streets. This is a significant benefit for public health, potentially leading to a considerable reduction in urban air pollution and related respiratory illnesses. Furthermore, the quieter operation of electric engines helps to decrease the constant noise pollution that characterizes many Vietnamese cities, contributing to a more pleasant urban environment.

However, a closer look reveals a more complex picture. The environmental credentials of an electric motorbike are heavily dependent on the source of its electricity. In Vietnam, a large portion of the national power grid is still fueled by burning fossil fuels, particularly coal. Consequently, charging an electric motorbike often means the pollution is simply displaced from the vehicle's tailpipe to the smokestack of a power plant. Another major concern involves the batteries. The production of lithium-ion batteries is an energy-intensive process that relies on mining rare minerals. More importantly, the disposal of expired batteries presents a serious environmental hazard. They contain toxic materials that can contaminate soil and water if not managed correctly.

From a practical and economic standpoint, the choice is also not straightforward. Owners of electric motorbikes enjoy lower running costs, as charging with electricity is generally cheaper than buying petrol, and the simpler engines require less maintenance. However, the initial purchase price of an electric model is often higher than that of a comparable petrol motorbike. Additionally, users may experience 'range anxiety'—the fear of the battery running out of power before reaching a destination or a charging station, a concern that is less prevalent with the widespread availability of petrol stations.

In conclusion, while electric motorbikes represent a positive step towards cleaner urban transport in Vietnam, they are not a magical cure-all. Their true 'green' impact is compromised by the country's reliance on fossil fuels for electricity and the unresolved challenges of battery production and disposal. As technology evolves, particularly in renewable energy and battery recycling, their environmental benefits will undoubtedly grow. For now, they are a promising but imperfect part of a larger, more complex journey towards a sustainable future.