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.

I’m not Chinese, but I love Chinese New Year. There are many fun New Year     1     (celebrate), but nothing quite matches the excitement of the lion dance which can wake up the spirit     2     (complete).

The sound of the drums,       3     you can feel throughout your entire body, is quite inspiring. The two performers are very flexible. But it is actually very difficult as the lion head is very heavy and being the     4     (low)part of the lion is tiring as he has to bend his back and also carry     5     person in front sometimes. The lion head is made with paper over a bamboo frame,       6     (cover)in gauze (纱布), and decorated with beautifully-colored materials.

The lion dance     7     (believe)to have first appeared in the Qianlong Emperor's dream during his Southern tour, and he ordered an animal     8     (make)in the likeness of his description and used in festivals from then on.

I love all about the lion dance. The other day, I saw a film about a left-behind teenager who insisted on pursuing his dreams despite difficulties and     9     (succeed)in lion dance. As Master Xu translates: “Heaven has made us talents; we’re not made     10     vain.”

Citizen scientists don't     1     （usual）need special training or equipment. It may not even matter where they live. Often, projects are open to people of all     2     （age）. Many participants（参与者）are kids.

“This is an important, real way for young people to take part in science     3     is useful and important,” Darlene Cavalier says. She founded a website     4     （call）SeiStarter. It helps people find projects they might like to take part in.

For NASA's GLOBE Observer program, volunteers use     5     app on a mobile device（设备）to submit（提交）cloud observations. While satellites photograph clouds     6     above, volunteers study them from below. “By     7     （combine）the two, we get a more complete picture," says Jessica Taylor, of NASA. Researchers use the information       8     （learn）about weather and climate change.

There are thousands of citizen science projects to choose from. You can measure light     9     （pollute）, study the diet of ants, or locate bees. Sometimes, volunteers gather information from their own backyard. Other projects happen online. One     10     （provide）underwater images of beluga whales（白鲸）. Volunteers then tell things like each whale's age and gender.

In December 2018, a bunch of friends and I went to Europe to travel. Upon arrival in Vienna, we got the keys to the house from its owner. The     1     (decorate) of the house was quite good.

In Vienna, if anyone wants to copy a key, he or she is expected     2     (prove) their ownership of the property (房产) the key is for. It’s also really expensive. An ordinary key usually costs 150 euros (1.170 yuan). As the person in charge of the keys, I had a great responsibility.

    3     next day, we went everywhere, including the Sisi Museum and a coffee shop in the city center,     4     had dinner in a fancy restaurant. We felt quite relaxed. While we     5     (enjoy) dinner, my friends came up to me, asking for the keys so they could leave early. It was then that I realized that I’d lost them.

The host asked us to give him 300 euros to cover the cost of a new set of keys. We made a complaint about it but we had to pay the money. So, hoping to get our money back, we decided to do some detective work     6     our own.

I wrote an email to the Sisi Museum in the middle of the night, wondering whether the staff had found them. Early in the morning, I received their reply, saying that they had not.

    7     (fortunate) in the end, the keys were found in a souvenir shop. The host even said congratulations to us.

Though we saw many great     8     (sight) in Europe, the most     9     (value) thing about my trip was this lesson I learned: Never lose your keys in Vienna. Your keys ought to     10     (take) good care of.