Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-75

The construction of a spider's web is one of nature's most impressive engineering feats. A spider creates its web using a special protein-based silk, a material that comes from (35) __________ spinnerets, which are special organs on its abdomen. This silk is not only strong but also incredibly flexible, allowing the web to withstand wind and the struggles of trapped insects. The entire process follows a logical and predictable sequence of steps, resulting in a structure that is both beautiful and highly functional for catching prey.

The process (36) __________ when the spider releases a single, thin thread of silk into the wind, hoping it will catch onto a distant object like a branch or a leaf. This first thread, known as the bridge line, is incredibly (37) __________ but strong. Once the end of the thread attaches to a surface, the spider pulls it tight and secures it, forming the first foundation of its new home. This initial step is critical and depends heavily on air currents.

Next, the spider walks carefully (38) __________ the new bridge line, often reinforcing it with a second or third thread to make it stronger. From the center of this bridge line, it drops another thread downwards, attaching it to a lower point to create a 'Y' shape. This forms the first three radial lines of the web. (39) __________, the spider proceeds to build the outer frame and adds more radial lines, which spread out from the center like the spokes of a wheel.

With the frame and radial lines complete, the spider begins to spin a temporary, non-sticky spiral. This auxiliary spiral starts from the center and moves outwards, acting as a guide and providing stability during construction. It is not very (40) __________ at trapping insects. Once this is done, the spider starts its journey again from the outside edge, this time laying down the capture spiral, (41) __________ is coated with a sticky substance designed to catch prey. As it lays the sticky line, it removes the temporary spiral.

Finally, with the intricate structure complete, the spider will often sit in the center of the web or hide nearby, keeping a (42) __________ watch for the vibrations made by an insect caught in the sticky threads. The web is not just a trap but also a complex communication system, telling the spider the size and location of its next meal. This remarkable process showcases the spider's innate ability as a master builder, turning simple silk into a sophisticated tool for survival.

The term '5G' is everywhere, but what does it actually mean for you and your smartphone? Simply put, 5G is the fifth generation of mobile network technology. It represents a significant leap forward from the 4G networks we use today. Its two most celebrated promises are incredible speed and extremely low latency. While faster downloads are easy to understand, the combination of these two advancements is set to unlock a new world of possibilities, changing not just how fast you can stream a video, but the very nature of the apps and services you use every day.

Let's talk about speed. 5G networks are designed to be drastically faster than 4G. Imagine downloading a full-length high-definition movie in a matter of seconds, not minutes. For a teenager who loves watching videos on the go, this means no more frustrating buffering circles. You'll be able to stream 4K videos seamlessly, even in crowded areas. This raw speed enhances existing activities, making your current digital life smoother and more efficient, but the real revolution lies beyond just making things faster.

The second key feature of 5G is its ultra-low latency. Latency is the delay between sending a signal and receiving a response. With 4G, this delay can be noticeable, especially in real-time applications. 5G reduces this lag to almost zero. Why does this matter? It is the key that unlocks technologies like cloud gaming. With low latency, you can play graphics-intensive games on your phone, with the actual processing happening on a powerful remote server. It also makes highly responsive Augmented Reality (AR) applications possible, where digital information is overlaid onto the real world through your phone's camera without any jarring delay.

This technological shift is not just happening in other countries; it's arriving in Vietnam. Major mobile carriers like Viettel and Vinaphone are actively expanding their 5G trial networks. These are currently concentrated in major urban centers like Hanoi and Ho Chi Minh City, as the companies prepare for a future nationwide launch. This means Vietnamese teens will soon be among the first to experience these new capabilities firsthand, moving from hearing about 5G to actually using it.

However, the transition won't happen overnight. For 5G to work, new infrastructure needs to be built, a process that takes time and investment. Furthermore, not all current smartphones are 5G-compatible; many users will need to upgrade their devices to access the new network. So, while the 5G future is exciting and rapidly approaching, its widespread availability for every user will be a gradual process rather than an instant switch.