The world’s largest transparent spherical neutrino (中微子) detector has officially begun operation in Jiangmen, Guangdong province. This major scientific project, known as the Jiangmen Underground Neutrino Observatory (JUNO), is built 700 meters below the surface. Its main purpose is to detect neutrinos produced by the nearby Taishan and Yangjiang nuclear power plants, located 53 kilometers away, and to measure their energy spectrum with record-breaking precision. The launch of JUNO represents an important advancement in the study of particle physics, astrophysics, and cosmology.

Neutrinos are among the most mysterious particles in the universe. They are often referred to as “ghost particles” because they carry no electric charge and have nearly no mass, making them extremely difficult to detect. Despite these challenges, studying neutrinos is crucial to understanding some of the most fundamental questions about the nature of matter and the evolution of the universe. One of the key goals of JUNO is to determine the mass ordering of the three known types of neutrinos.

The detection technology used in JUNO is both advanced and innovative. At the heart of the observatory is a giant acrylic sphere filled with 20,000 tons of liquid scintillator (闪烁体) — a special fluid that emits faint flashes of light when neutrinos interact with it. This sphere is surrounded by 45,000 highly sensitive photomultiplier (光电倍增器) tubes that detect these tiny light signals. The entire facility is shielded by a deep underground layer of rock and a large water pool to block interference from other particles. This setup allows scientists to gather accurate data about the energy and types of neutrinos.

JUNO is not just a Chinese project — it is the result of extensive ___△___. More than 700 scientists and engineers from 74 institutions across 17 countries and regions have contributed to its construction. With an estimated operational lifetime of 30 years, JUNO is expected to greatly expand our knowledge of neutrinos and their role in the universe. It follows the success of China’s earlier Daya Bay Neutrino Experiment, which made significant discoveries about neutrino oscillations. Together, these projects demonstrate China’s growing contribution to global basic scientific research.

1.1. What is talked about JUNO in Para. 1?

A Its location and purpose.

B Its international team.

C Its technical challenges.

D Its future upgrade plans.

解析：选A。A 细节理解题。第一段主要介绍了JUNO的地理位置（广东江门、地下700米）、官方名称以及其主要科学目的（探测核电站中微子、精确测量能谱）。故选A。

2.2. What’s the feature of neutrinos?

A Heavy and visible.

B Charged and massive.

C Inactive and harmless.

D Massless and hard to detect.

解析：选D。D 细节理解题。第二段明确指出中微子“carry no electric charge and have nearly no mass, making them extremely difficult to detect”（不带电荷、几乎无质量、极难探测）。故选D。

3.3. What’s the key element in the detection?

A The nuclear power plants.

B The liquid scintillator.

C The deep rock layer.

D The water pool.

解析：选B。B 推理判断题。第三段解释了探测原理：中微子与液体闪烁体（liquid scintillator）发生反应才会产生光信号，这是整个探测过程最核心的一环。光电倍增管是探测光信号，岩层和水池是屏蔽干扰，它们都是为探测这个关键信号服务的。故选B。

4.4. Which of the following phrases can be put in the “___△___”?

A government funding

B international cooperation

C public participation

D industrial support

解析：选B。B 推理判断题。空格后的句子提到来自17个国家和地区、74个机构的700多名人员参与了建设，这显然是“国际合作”（international cooperation）的具体体现。故选B。