Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-93

The life cycle of a frog is a remarkable journey of transformation, known as metamorphosis. This process begins with a large cluster of eggs, called frogspawn, laid in or near water. From each jelly-like egg hatches (21) __________ tiny aquatic creature called a tadpole. At first, it looks more like a small fish than a frog, possessing a long tail for swimming and lacking any limbs.

During its initial stage, the tadpole is perfectly adapted for life underwater. It breathes using special organs called (22) __________, which extract oxygen directly from the water, just as fish do. Its primary diet consists of algae and other small plant matter, which it scrapes from surfaces with its tiny mouth. The tadpole spends its days swimming actively, growing bigger and stronger in preparation for the dramatic changes that are to come.

Gradually, the transformation begins. First, back legs start to sprout, and a little later, front legs appear. (23) __________, the tadpole's body begins preparing for life on land. As these limbs grow, the tadpole starts to take on the appearance of a miniature frog, although it still has its long, powerful tail. This intermediate stage is often called a 'froglet'.

Internally, even more significant changes are occurring. The gills that were essential for underwater life begin to disappear as a pair of lungs develops. Its body starts (24) __________ its long tail for energy and nutrients, causing it to shrink. A biologist once explained that the tail was gradually absorbed, not simply dropped off. This absorption is a crucial part of fueling the final, energy-intensive stage of metamorphosis.

Finally, the tail vanishes completely. If the tadpole did not complete this final stage successfully, it would not be able to survive out of the water. With its new lungs, strong legs, and no tail, the young frog is now fully equipped for a life on land. It can hop away from the water's edge to hunt for insects, a very different diet from what it ate as a tadpole. The transformation from an aquatic herbivore to a terrestrial carnivore is, to all intents and purposes, complete.

Cities are bustling hubs, often characterized by towering buildings and dense populations. Yet, nestled within this urban sprawl are essential pockets of nature: urban green spaces. More than just a patch of grass or a few trees, these areas, often referred to as a city's "green lungs," are vital for the well-being of both the environment and its inhabitants. From sprawling parks to community gardens, these green havens offer a crucial antidote to the concrete jungle, providing essential environmental services and fostering healthier communities. [I]

Globally, urban planners recognize that these verdant spaces are indispensable. Trees and plants within parks act as natural air filters, absorbing pollutants and releasing oxygen, significantly improving air quality. They also help combat the "urban heat island effect" by providing shade and cooling the environment, making cities more comfortable. Furthermore, green spaces are critical for preserving biodiversity, offering crucial habitats for local wildlife, thereby contributing to a city’s ecological balance and resilience against climate change. [II]

The importance of green spaces resonates particularly strongly in densely populated cities like Ho Chi Minh City. As urban areas expand rapidly, the premium placed on natural surroundings becomes evident. Major new developments, such as Vinhomes Central Park, have strategically leveraged the appeal of their large green areas situated beside the serene Saigon River. These meticulously designed parks are not just an aesthetic addition but a core selling point, attracting residents seeking a balance between modern urban living and access to nature. [III]

For teenagers, these urban oases offer tangible, everyday benefits. Where do you go to unwind after school or meet up with friends on a weekend? Often, it's a local park or green area. These spaces serve as vital social hubs, providing safe, open environments for recreation and social interaction away from screens. Beyond social connections, spending time in nature has profound positive effects on mental health, reducing stress and anxiety, improving mood, and boosting cognitive function. These hidden benefits contribute significantly to overall well-being. [IV]

In conclusion, urban green spaces are far more than mere decorative elements; they are fundamental components of a thriving city. They are the air purifiers, the cooling systems, the biodiversity havens, and the social gathering points that make urban life sustainable and enjoyable. As cities continue to grow, the deliberate creation and preservation of these "green lungs" will be paramount. Investing in parks and gardens means investing in cleaner air, healthier citizens, and more resilient, livable urban environments for everyone.