Brazil’s Rio de Janeiro and a startup use drones(无人驾驶飞机) to help reforest(重新造林) Brazil.
Drones fly over difficult terrain(地形). They get important information about soil, animals, and plants. Artificial intelligence (AI) helps with this. After this, they find places where to put seeds. The drones work 100 times quicker than working by hand. They can spread(传播) 180 seeds every minute.
This makes reforestation much faster.

1.What does the underlined word “They” refer to?

A Drones.

B Seeds.

C Animals.

D Plants.

解析：选A。A词意指代题。根据划线单词前面的“Drones fly over difficult terrain.”可知，这些无人机在难以通过的地带上飞行，它们（无人机）获取有关土壤、动物和植物的重要信息。故选A。

2.What can we know about drones?

A They work without help.

B The terrain makes them stop working.

C They work slower than working by hand.

D They find places where to put seeds.

解析：选D。D细节理解题。根据第二段第一句“Drones fly over difficult terrain.”可知，复杂的地形并没有影响无人机的工作，B错误；根据第二段第三句“Artificial intelligence (AI) helps with this.”可知，该项目借助无人机和人工智能技术进行，并不单一借助无人机，A错误；根据第二段第五句“The drones work 100 times quicker than working by hand.”可知，无人机的工作速度是人工播种的100倍，C错误；根据第二段第四句“After this, they find places where to put seeds.”可知，无人机会精准确定种子投放目标区域。故选D。

3.How many seeds can drones spread every minute?

A 100.

B 180.

C 18.

D 10.

解析：选B。B细节理解题。根据第二段最后一句的“They can spread 180 seeds every minute.”可知，无人机每分钟可以播种180粒种子。故选B。

4.From the text, we can know the project(项目) is ______.

A terrible

B slow

C helpful

D expensive

解析：选C。C推理判断题。根据文章最后一句的“This makes reforestation much faster.”可知，该绿化项目使巴西里约山地植树造林速度加快，帮助提高绿化率，因此是有帮助的。故选C。

5.Where can we read the passage?

A In a diary.

B In a newspaper.

C In a postcard.

D On a stamp.

解析：选B。B推理判断题。根据全文内容可知，本文主要讲了由于山林中人工植树难度较大，里约热内卢正在探索借助AI等最新的科技成果，来帮助提高绿化率，属于新闻报道，我们可以在报纸上读到。故选B。