China has announced plans for a space mission to test whether it is possible to change an asteroid’s path by striking it with a spacecraft. The news was revealed by Wu Weiren, a leading scientist in China’s lunar exploration program, during an international conference on deep space exploration that took place in Hefei, Anhui Province.

The mission will follow a method known as “fly-along – impact – fly-along.” It involves two spacecraft: an observer and an impactor. First, the observer will approach the target asteroid to conduct close-up examinations and gather essential information. Then, the impactor will strike the asteroid at a very high speed. Both spacecraft, along with ground-based and space-based equipment, will use high-quality cameras to record the entire collision. Scientists expect to accurately measure changes in the asteroid’s movement and physical structure after the impact.

Asteroids are small, rocky bodies that orbit the Sun. Our solar system contains billions of such objects. They are often referred to as “fossils” from the early solar system because they carry clues about how the planets formed. Although asteroids contain valuable resources such as metals and water ice, those that pass near Earth could also pose a major threat to our planet. This is the reason why China is developing technology to help protect Earth from potential asteroid impacts.

In recent years, China has launched several projects related to asteroid exploration and planetary defense. For instance, in May, the Tianwen 2 probe was sent into space with the aim of collecting samples from a near-Earth asteroid. Additionally, Chinese scientists are developing a monitoring and warning system to detect potentially dangerous asteroids at an early stage. China also intends to cooperate with other countries by sharing data and supporting joint efforts in monitoring and research. The ultimate goal is to ensure that we are well prepared to act effectively should an asteroid ever endanger Earth.

1.1. What is the main purpose of China’s planned space mission?

A Collecting asteroid samples.

B Altering asteroid’s course.

C Studying the solar system’s history.

D Building a new camera system.

解析：选B。B 细节理解题。第一段开篇明确指出该任务的目标是测试“whether it is possible to change an asteroid’s path”。选项B中的“Altering its course”(改变其轨道)是原文“change an asteroid’s path”的同义替换。故选B。

2.2. What does the term “fly-along” most likely refer to in the text?

A Flying around the impactor.

B Accompanying and observing.

C Entering the asteroid’s orbit.

D Returning to Earth quickly.

解析：选B。B 词意指代题。根据第二段描述，任务模式是“fly-along–impact–fly-along”，并提到一个观察器（observer）会先接近小行星进行检测，之后撞击器（impactor）才进行撞击。因此，“fly-along”在此语境中最贴切的含义是“伴随飞行并进行观测”。故选B。

3.3. Why are asteroids considered valuable to scientists?

A They are made of precious metals.

B They are close to Earth.

C They help explain planet formation.

D They contain water for future use.

解析：选C。C 推理判断题。第三段提到小行星被称为“化石”是因为它们携带了行星形成过程的线索（carry clues about how the planets formed）。选项C“帮助解释行星的形成”是对这一信息的同义转述，准确抓住了其科学价值。故选C。

4.4. What is the main idea of the last paragraph?

A China has started multiple space projects.

B China is working alone to defend Earth.

C China launched Tianwen 2 to collect samples.

D China aims to be ready for asteroid threats.

解析：选D。D 主旨大意题。最后一段提到了多个项目（如天问二号、监测系统）、国际合作，并总结其最终目标（ultimate goal）是做好有效应对小行星威胁的准备。D项全面概括了该段的中心思想，其他选项都只是段落中提到的某个细节。故选D。