In China, Tree Planting Day falls on March 12, but more often people plant trees during Qing Ming Festival in early April. Newly-planted trees can survive more easily with a     1     (warm) climate and frequent spring rainfall at that time.

China set March 12     2     the National Tree-Planting Day in 1979 to memorize Sun Yat-sen (孙中山),     3     died on March 12, 1925. Sun had called for planting trees.

Since 2013, President Xi Jinping has joined Beijing citizens in tree planting activities for nine years in a row. President Xi called on the public     4     (stick) to the tradition of planting trees in spring. “Students should establish an awareness of protecting     5     environment and cherish the green plants,” Xi said in 2017 when     6     (attend) a tree planting activity in Chaoyang district of Beijing.

China has seen a remarkable     7     (grow) in forest resources and afforestation(造林) projects. Nationwide voluntary tree planting campaigns in China over the past four decades     8     (see) increased participation by members of the public and nearly 79 billion trees have been planted. The campaign has made China the country with the largest increase in forest resources and the largest area of     9     (plant) forests.

In the future, China will launch more effective     10     (measure) to fulfill the country’s climate commitment to peak (达到峰值) carbon dioxide emissions before 2030 and achieve carbon neutrality (碳中和) before 2060.

2 . More than half the world’s population live in cities, and by 2050 the UN expects that proportion to reach 68%. This means more homes, roads and other infrastructure. In India alone, a city the size of Chicago will have to be developed every year to meet demand for housing. Such a construction increase is a bad sign for dealing with climate change, because making steel and concrete, two of the most common building materials, generates around 8% of the world’s CO2 emissions (排放). If cities are to expand and become greener at the same time, they will have to be made from something else.

Wood is one of the most promising sustainable (可持续的) alternatives to steel and concrete. It is not, however, everyday wood that is attracting the interest of architects.

Rather, it is a material called engineered timber. This is a combination of different layers, each designed to meet the requirements of specific parts such as floors, panels and beams (横梁). Designers can use it to provide levels of strength like steel, in a product that is up to 80% lighter. In addition, engineered timber is usually made into large sections in a factory for future use, which reduces the number of deliveries to a construction site.

According to Michael Ramage of the University of Cambridge, a wooden building produces 75% less CO2 than a steel and concrete one of the same size. However, if building with wood takes off, it does raise concern about there being enough trees to go round. But with sustainably managed forests that should not be a problem, says Dr Ramage. A family-sized apartment requires about 30 cubic metres of timber, and he estimates Europe’s sustainable forests alone grow that amount every seven seconds. Nor is fire a risk, for engineered timber does not burn easily. Besides, fireproofing layers can be added to the timber. All in all, then, it looks as if wood as a building material may get a new lease of life.