3 . The worldwide 20th century “Green Revolution”, which saw huge year-by-year increases in global grain yields (产量),was fueled by the development in the 1960s of new high-yielding dwarfed (矮小) varieties known as Green Revolution Varieties (GRVs).

These dwarfed GRVs are common all over the world in today’s wheat and rice crops. Because they are dwarfed, with short stems, GRVs devote relatively more resources than tall plants to the growth of grains rather than stems, and are less likely to suffer yield losses from wind and rain damage. However, the growth of GRVs requires farmers to use large amounts of nitrogen fertilizers (氮肥) in their fields. These fertilizers are costly to farmers and cause extensive damage to the natural environment. The development of new GRVs combining high yields with reduced fertilizer requirements is thus a global agricultural goal.

Researchers at the University of Oxford and the Chinese Academy of Science have discovered for the first time a gene that can help reach the goal. Comparing 36 different dwarfed rice varieties, the researchers identified a novel natural gene that helps increase the rate at which plants make use of nitrogen from the soil. This gene, called GRF4, can increase the amount of a protein (蛋白质) in plant cells. GRF4 is actually a promoter that encourages the activity of other genes—genes that promote nitrogen uptake (摄入). Professor Harberd said, “Increasing GRF4 levels could contribute to an increase in the grain yields of GRVs, especially at low fertilizer input levels.”

The researchers say the latest rice variety containing GRVs should now become a major target for farmers in increasing crop yields and fertilizer use efficiency, with the aim of achieving the global grain yield increases necessary to feed a growing world population at a reduced environmental cost. It is very urgent at the moment.

Professor Harberd added, “This study is an example of how studying fundamental science objectives can lead rapidly to potential solutions to global challenges. It shows how the discovery can enable chances for food security and future new green revolutions.”

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.”

10 . Skeleton is one of the three sliding sports at the Beijing 2022 Olympic Winter Games, alongside the luge(单雪橇)and bobsleigh(大雪橇). With only six medals up for grabs, skeleton has the fewest events at the Winter Games—which means competition will be fierce.

The sport of skeleton has its roots in the most popular winter pastime: sleighing. In the mid-19^th century, British and American holidaymakers built the first toboggan(平底雪橇)run in Davos in 1882, and thus the sport of sleighing began.

Two years later, in 1884, the famed Cresta Run—a natural ice skeleton racing toboggan track—was built in St. Moritz, Switzerland(the course has hosted the annual Grand National championships since 1885).

In 1892, a new sledge made entirely of steel was introduced, and some claim that its bony appearance gave the sledge and the sport the name ‘skeleton’.

Men’s skeleton was first introduced on the Olympic program in the 1928 Games in St. Moritz. But due to the sport only being available at the Cresta Run at the time, it fell into obscurity(默默无闻)while the luge and bobsleigh grew in popularity. However, in 2002, the skeleton was reintroduced as a men’s and women’s event at the Salt Lake City Winter Olympics, and has remained a part of the Olympic program ever since.

While Great Britain has the most medals(nine)in skeleton competition at the Olympics, the top spot belongs to the United States(eight medals)by virtue of having four silvers to Great Britain’s one(both nations have three golds, while Britain has five bronze medals, and the United States one).

Great Britain is the only nation to have won a medal every time skeleton has featured at the Olympic Games, and has won at least one medal in each of the five contests of women’s skeleton since its introduction.