Just as soil (土壤) provides energy for trees, a substrate (基质) works the same way for mushrooms. Farmers usually use trees to make the substrate, which hurts the environment. But now, thanks to China’s “Juncao” (菌草) technology, fewer trees are cut down to do this.

Juncao is a grass that can grow up to 8 meters tall. To grow the mushrooms, people first collect the grass and make it into powder (粉末). Then, they mix the powder with water and other things to make the substrate. It helps mushrooms grow quickly. Later on, people can eat the mushrooms or sell them.

This “magical” grass has become a popular plant in Africa. After being brought there, Juncao has helped many people live a better life. For example, in Rwanda, thousands of families are planting Juncao for a living. Thanks to it, many of these families are making much more money than before.

Besides helping grow mushrooms, Juncao has many other things to offer. It can be turned into hard board strong enough to make buildings. It is also good food for animals, like cows and sheep. What’s more, Juncao can help solve environmental problems. Its deep roots (根) help make the soil stronger. When it rains, there is less chance of the soil being washed away.

1.1. Which is true about the substrate made from Juncao?

A It improves soil quality.

B It provides energy for trees.

C It is strong to make buildings.

D It is friendly to the environment.

解析：选D。D 细节理解题 文章第一段明确指出，传统的基质用树木制作会破坏环境（“hurts the environment”），而菌草技术的出现使得“fewer trees are cut down to do this”。由此可推知，用菌草制作的基质对环境是友好的。A选项（改善土壤质量）是菌草根系的直接作用，不是基质的作用。B选项（为树木提供能量）与基质为蘑菇提供能量的功能混淆。C选项（坚固到可以建房）指的是菌草本身可以被加工成板材，而不是基质。

2.2. How does the writer show Juncao is popular in Africa?

A By listing numbers.

B By telling a story.

C By giving an example.

D By raising questions.

解析：选C。C 细节理解题 文章第三段为了说明菌草在非洲很受欢迎，作者使用了“For example, in Rwanda...”的句式，具体描述了卢旺达有成千上万的家庭以此为生并增加收入，这是典型的举例论证法。A选项（列数字）虽然有“thousands of families”这样的数字，但其核心是为例子服务，并非主要手法。B选项（讲故事）和D选项（提问题）在文中均未使用。

3.3. What does the text mainly tell us about Juncao?

A Its forms.

B Its advantages.

C Its products.

D Its challenges.

解析：选B。B 主旨大意题 文章主要介绍了菌草的多方面好处（优点）。第一段讲它替代树木做基质，保护环境；第二段讲它如何用于种植蘑菇；第三段讲它在非洲帮助人们改善生活；第四段则系统列举了它在工业（做板材）、农业（作饲料）、生态（固土保水）等多方面的其他优点。因此全文核心是介绍菌草的优点。A选项（它的形态）、C选项（它的产品）只是优点的一部分具体体现，不够全面。D选项（它的挑战）文中并未提及。