Scientists in Brazil have found a new method to clean water. They can use seeds (种子) from a tree to clean dirty water. The water often has tiny plastic pieces in it. These are called microplastics. Microplastics are tiny bits of plastic, less than 0.5 cm long. They can be too small to see. They can get inside the bodies of living things, including humans.

There is a kind of tree called a Moringa tree, which grows well in hot areas and lots of people eat its leaves and seeds. For years, scientists have studied if the seeds can work on microplastics to clean dirty water. Now, they have good news. In their latest study, the team found that a substance (物质) from the seeds was very useful. When they put this substance in the water, the microplastics would stick together. So it was easier to take them out with a filter (滤水器).

The scientists first tested the method on tap water (自来水). They added microplastics to the water. Then, they compared their new method with a popular one. The popular method is more harmful to the environment. Surprisingly, both methods cleaned the water well. In some types of water, the Moringa seeds worked even better!

Now, the team is testing the seeds on water that is collected from rivers in Brazil. The results show that this new method works well for river water, too. The scientists say it is a better choice for the environment, because it does not harm nature as the popular method does.

However, more tests are still needed. Scientists want to see if this new method can clean large amounts (数量) of water.

1.1. What have the scientists in Brazil found?

A Microplastics are small.

B Seeds can clean water.

C Plastics are widely used.

D Leaves can feed people.

解析：选B。答案：B【细节理解题】 线索：Scientists in Brazil have found a new method to clean water. They can use seeds from a tree to clean dirty water. 解析：巴西科学家发现树木种子可以净化污水。A 只是文中一个细节，不是核心发现；C、D 和题干问题无关。

2.2. How does the substance from the seeds work on microplastics?

A By letting them go down.

B By breaking them into pieces.

C By turning them into gas.

D By making them stick together.

解析：选D。答案：D【细节理解题】 线索：When they put this substance in the water, the microplastics would stick together. 解析：种子内的物质能让微塑料聚集粘在一起。

3.3. How is the new method different from the popular one?

A It is easier for labs to use.

B It is more popular with people.

C It is better for the environment.

D It is cheaper for scientists to test.

解析：选C。答案：C【细节理解题】 线索：The scientists say it is a better choice for the environment, because it does not harm nature as the popular method does. 解析：新方法相比传统方法，对环境更加友好。

4.4. On what water are the scientists testing the seeds now?

A River water.

B Tap water.

C Sea water.

D Bottled water.

解析：选A。4.答案：A【细节理解题】 线索：Now, the team is testing the seeds on water that is collected from rivers in Brazil. 解析：科学家当下正在河水样本上开展测试。

5.5. What is needed for the next step of the study?

A Planting more trees in Brazil.

B Collecting more Moringa leaves.

C Setting up more research teams

D Testing on large amounts of water.

解析：选D。答案：D【细节理解题】 线索：However, more tests are still needed. Scientists want to see if this new method can clean large amounts of water. 解析：下一步研究需要测试该方法处理大量水体的能力。