根据下面短文，在空白处填入正确的选项。 It's March 12th. Li Li and Lin Tao aredigging on a hill nor far from their school. In China, people across thecountry plant trees 1 onthis day.
The idea of planting trees was first putforward in 1911 by Sun Zhongshan, the great 2 in China's history. He said moretrees were needed as a 3 against flood(洪水)and drought. In1915, April 5th was named as Tree Planting Day.Then, in 1979, theday 4 toMarch 12th, to 5 the date on which Sun Zhongshan died.
＂Everyone has heard of the Great Wall of China,＂says Li Li. ＂But have you heard of the GreenWall of China? That's the biggest tree planting 6 of all. ＂The Gobi Desert in the north of China was 7 every year. So in 1978, a tree plantingproject was started to 8 Gobi spreading. The government and localfarmers have been planting millions of trees to build a great green＂wall＂ along the edge of the desert.
＂Tree planting has become a tradition in Chinanow,＂says Lin Tao. ＂Almosteveryone does it on March 12th. Many people also plant a tree on a 9 day. My parents planted a tree when startedschool. And my cousin planted 10 on his wedding (婚礼)day. We do it for the environment and for ourselves.＂
