Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-110

During a powerful storm, we often (21) __________ a spectacular display of light and sound. A brilliant flash of lightning illuminates the sky, followed moments later by a deep rumble of thunder. This delay has led many people to wonder about the relationship between these two powerful natural forces.

It is a common misconception that lightning causes thunder, or that they are two separate events. In reality, lightning and thunder are two parts of the same single event: a massive electrical discharge in the atmosphere. The lightning is the flash of light, and the thunder is the sound wave created by the rapidly heated air. They are produced at the exact same moment.

The reason we see one before we hear the other is simple. This happens because light travels much faster than sound. Light moves at an incredible speed of about 299,792 kilometers per second, reaching our eyes almost instantly. Sound, however, is significantly slower, moving through the air at only about 0.343 kilometers per second. That is why there is a noticeable gap between seeing the flash and hearing the boom.

In the past, ancient cultures created myths to explain this. One story claimed that a sky god had thrown his hammer to create the flash, and the sound was the echo of the strike. Today, science gives us a clearer picture. In fact, you can (22) __________ how far away a storm is. For every three seconds you count between the lightning and the thunder, the storm is approximately one kilometer away.

If sound traveled as fast as light, we would see and hear the storm at the exact same moment. For many young learners, understanding this simple principle of physics makes the science of storms as (23) __________. So, next time you are safely indoors during a storm, remember (24) __________ shelter and you can try counting the seconds yourself to see science in action.

The rise of remote work has fundamentally reshaped how and where people live and earn a living. This global shift has given birth to "digital nomads," individuals leveraging technology to work from anywhere. [I] As these foreigners increasingly choose vibrant destinations as long-term bases, a crucial question arises: is their presence ultimately beneficial or detrimental to the local community?

On the positive side, digital nomads often inject significant economic vitality. [II] They patronize cafes, restaurants, and local shops, spending money that directly supports small businesses and creates jobs for residents. Their desire for authentic experiences can lead them to explore less-traveled areas, spreading economic benefits. Furthermore, their diverse backgrounds foster rich cultural exchange, introducing new perspectives and ideas, enriching for both visitors and locals, sparking conversations.

[III] However, the influx of digital nomads is not without challenges. One frequently discussed concern is the potential for rising costs of living. Increased demand for housing, services, and everyday goods can drive up prices, making it difficult for local residents, especially young people and families, to afford their own cities. This can lead to gentrification, where traditional businesses are displaced by establishments catering to foreign tastes, and unique neighborhood character erodes, becoming less authentic.

In Vietnam, cities like Da Nang and Hoi An have become particularly attractive hubs for these remote workers, a trend widely covered by local media like VnExpress International, sparking vigorous public discussions. Locals often experience firsthand the tangible effects, from bustling cafes to changing rental markets. While many appreciate the economic boost and global connections, others express concerns about maintaining cultural integrity and ensuring development remains inclusive, benefiting all segments, not just newcomers.

Ultimately, the impact of digital nomads is complex, presenting opportunities and challenges for urban centers. It underscores the need for thoughtful urban planning and policies that harness economic benefits while mitigating negative social and economic consequences. [IV] As you observe these global workers in your city's cafes, consider the multifaceted ways they contribute to, and sometimes reshape, the place you call home, prompting ongoing conversations about balance, growth, and community.