1 . King Canute couldn’t stop the ocean’s tide from rolling in — can Africa hold back the desert? That’s certainly what the continent is trying to do with its proposed “Great Green Wall”, 8,000 km worth of trees that officials hope will stop the advancement of the Sahara desert, which has been rapidly expanding southward.

The project aims to plant 100 million hectares of trees by 2030 across the entire width of Africa. The initiative is a decade in, and around 15% completed, and there have already been benefits for many communities and wildlife. It’s bringing life back to the continent’s degraded landscapes, providing not only food security and jobs but a reason to stay for the millions who live along its path.

Efforts will be concentrated along the Sahel, a region in Africa that lies between the Sahara in the north and the more tropical savanna in the south. Burkina Faso, Cameroon, Chad, The Gambia, Guinea Mauritania, Mali, Niger, Nigeria, and Senegal all form the Sahel region, where there are up to 50 million people who still live as nomads(游牧民), depending on cattle to sustain their livelihoods. It’s one of the poorest places on the planet: a region of hunger, conflict, and low job prospects, made even harder by the ongoing drought.

At a science conference held in December, experts estimated that the wall could have far-reaching influence on weather patterns. Climate models presented at the American Geophysical Union’s autumn conference forecast that the finished wall could increase rainfall fourfold in the Sahel and lower average summer temperatures over most of northern Africa. However, the hottest sections of the desert may become even hotter, increasing by up to 1.5 °C.

The wall may seem like a moonshot, but all the best ideas usually are. As Thomas Sankara, former president of Burkina Faso said in 1985, “You cannot carry out fundamental change without a certain degree of madness...The courage to turn your back on the traditional methods, the courage to invent the future.”

1. What’s the purpose of the “Great Green Wall”?

A．To protect the original landscapes.

B．To bring more wildlife to this region.

C．To increase the varieties of local plants.

D．To stop the Sahara desert from expanding.

2. What can we know about the Sahel region?

A．It is in the centre of the Sahara.

B．It is home to 50 million cattle.

C．It provides a lot of job opportunities.

D．It consists of many poor countries.

3. What impact would the wall have on weather patterns?

A．Free of drought in Africa.

B．More rainfall in the Sahel.

C．Lower temperatures all year round.

D．Cooler weather in the hottest areas.

4. What is the author’s attitude to the project?

A．Favorable.

B．Uncaring.

C．Critical.

D．Ambiguous.