Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHTN môn Tiếng Anh - Mã đề KHTN-49

(23) __________ This approach involves a few simple steps. Following them carefully helps you build momentum and stay motivated. (24) __________

A skyscraper is an incredibly tall building. The secret to its stability lies deep underground in its foundation. The primary purpose of a foundation is to transfer the building's enormous weight safely to the ground. Engineers (25) __________ a crucial role in designing these systems. For example, before the construction of The Shard in London (26) __________, they spent months studying the ground.

The ground beneath a skyscraper (27) __________ carefully to understand its properties. Depending on the soil, different foundations are used. One common type involves long columns called piles, (28) __________ are driven deep into the earth until they reach solid rock. These piles support the skyscraper's entire weight. (29) __________, if the rock is close to the surface, a shallower foundation might be enough. A strong foundation is therefore the most (30) __________ part of a skyscraper's construction, ensuring its safety for decades.

In cities across Vietnam, from Hanoi to Ho Chi Minh City, a green trend is growing. Young people are filling their rooms and favorite cafes with houseplants. This is not just for decoration; many believe these plants are natural air purifiers. Shops and social media often promote specific plants as being excellent at cleaning the air. But is this popular belief based on solid science, or is it more of a hopeful myth?

The idea that plants can clean indoor air comes from a famous 1989 NASA study. Researchers found that common houseplants could absorb harmful chemicals called volatile organic compounds (VOCs) from the air in a sealed laboratory chamber. This process happens as the plant takes in gases through its leaves and the microorganisms in the soil also play a part. The study was originally intended to explore life support systems for potential space stations.

However, translating these findings to a typical home or bedroom is complicated. The NASA experiment was conducted in a small, airtight chamber. Our rooms are much larger and have constant air exchange from windows, doors, and ventilation systems. Therefore, the cleaning effect of a few plants in a normal-sized room is actually quite minor. You would need an enormous number of plants—perhaps hundreds—to have a noticeable impact on air quality.

So, should you get rid of your plants? Absolutely not. While they may not be powerful air filters, houseplants offer other proven benefits. Studies show they can reduce stress, boost mood, and improve focus. They add beauty and a touch of nature to our urban lives. It's best to appreciate houseplants for these qualities, rather than relying on them to solve air pollution problems.

Biofuels, fuels made from plants like corn and sugarcane, are often seen as a green alternative to fossil fuels. (37) __________. However, this seemingly simple solution has sparked a major global debate, often called the "food versus fuel" dilemma. When farmers use land to grow crops for fuel, that same land cannot be used to grow food. (38) __________. As a result, the world's poorest populations may struggle to afford basic meals.

Moreover, the environmental advantages are not always clear-cut. (39) __________. For example, clearing forests to create new farmland for biofuel crops can release massive amounts of stored carbon into the atmosphere. (40) __________. Clearly, finding a sustainable path forward is a complex challenge.

A. This competition for agricultural land can drive up the price of essential foods

B. Therefore, the overall benefit to the climate is often debated

C. They are considered renewable resources, unlike finite fossil fuels

D. The process of growing and converting plants into fuel also requires significant energy