阅读下列短文，从下面每小题的 A、B、C、D四个选项中选出最佳选项。
In Gansu province, three generations of workers have worked hard to stop desertification.
Babusha,a big sand dune(沙丘) at the edge(边缘) of the Tengger Desert, was a big cause of sandstorms in the 1980s. The desert destroyed farmland and villages in its south, and affected more than 30,000 people. However, with the effort of"the six old men"and their children and grandchildren, now,a green belt, which is 10 kilometers long and 8 kilometers wide, has been built.
This project is time-consuning. Guo Chaoming and five other villagers first had the idea of renting 5,000 hectares (公顷) of sandy land to plant trees in 1981. Their original goal was to prevent sandstorms from destroying their crops. At the time, Guo, the oldest of the six, was already 61, while Zhang Runyuan, the youngest, was not yet 50.
At first, they planted 667 hectares of saplings (幼苗) . However, after the first sandstorm, no more than 30 percent survived. After countless failure, they successfully thought of the idea of burying wheat straw(埋麦秸) around trees to hold the sand.
Planting trees in desert is difficult, but taking care of them was even challenging. To protect the trees, they chose to live there for years, in a simple shelter they made from wooden poles and straw (木杆和稻草) . They used bricks(砖头) to support a cooking pot(灶台) , drank boiled water and ate steamed buns when hungry.
In the eyes of the six men, the Babusha forest farm became their most valuable possession. Even in the 1990s, when they were lack of money, they didn't cut down a single tree or grass to sell. Time passed by and four of the six passed away. But their children and grandchildren took up the torch and continued their work.
Now, the desert has changed into grassland and forest. The amount of plants has increased from less than 3% to more than 75%. In 2019, "the six old men"and their families were honored"Model of the Times"and"Most Beautiful Fighters" for their hard work.
