1 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

The Xi’an City Wall is the most complete city wall that has survived China’s long history. It     1     (build) originally to protect the city     2     the Tang dynasty and has now been completely restored (修复). It is possible       3     (walk) or bike the entire 14 kilometers.

We accessed the wall through the South Gate. The wall is 12 meters high and from here you can see streams of people moving inside and outside the City Wall.

After     4     (spend) some time looking at all the defensive equipment at the wall, we decided it was time for some action and what     5     (good) than to ride on a piece of history!

We     6     (hire) our bikes from the rental place at the South Gate. My bike was old and shaky     7     did the job. It took us about 3 hours to go all     8     way around the Xi’an City Wall. Supposedly you can do it in two hours, but we stopped at the different gates and     9     (watchtower) to take pictures or just to watch the local people going about their     10     (day) routines.

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.”

1. What can we know about dwarfed GRVs?

A．They have higher yield and taller stems.

B．They are a “double-edged sword”.

C．They are environmentally friendly.

D．They can be easily affected by weather.

2. What does “the goal” in Paragraph 3 refer to?

A．Increasing the rate of nitrogen use.

B．Producing cheaper nitrogen fertilizers.

C．Using fewer fertilizers to produce more grains.

D．Finding a gene to solve agricultural problems.

3. What can GRF4 directly do?

A．It promotes other genes' activity.

B．It increases the output of crops.

C．It takes in nitrogen from the soil.

D．It lowers fertilizer input levels.

4. What’s the urgent thing recently according to the researchers?

A．Decreasing the amount of fertilizers required by GRVs.

B．Encouraging farmers to adopt the new rice variety.

C．Calling on farmers to use effective fertilizers.

D．Focusing on the improvement of GRF4.

5. What’s the main idea of the text?

A．GRVs—a potential measure to achieve global food security.

B．The influence of agricultural development on the environment.

C．The importance of raising public awareness of global issues.

D．GRF4—foundation for new green revolutions.

8 . On the 100th anniversary of the Communist Party of China (CPC), red tourism has gained popularity among tourists who flood in to visit historic sites with a modern revolutionary heritage.

Jinggangshan

This is one of the most crucial and splendid chapters of history of establishing Red China as well as a unique and wonderful ecosystem, which is covered with rich forest, rugged peaks and several memorials to the Red Army. The best time to visit is between April and October, with the most temperature timing April and May when the large azaleas (杜鹃花) bloom.

Open: 8:00-17:00 (Feb. 16-Nov. 15). 8:00-16:30 (Nov. 16-Feb. 15)

Xibaipo

It is an old revolutionary base where the leadership of the Communist Party of China was stationed, drawing up the blueprint for a new country. A memorial hall was built to honor the memory of this site. The lake and the hill here add brilliance and beauty to each other and form pleasant scenery.

Open: Tuesdays to Sundays 9:30-17:00 (Xibaipo Memorial Hall)

The Nanhu Revolutionary Memorial Hall

A new exhibition is held with updated display approaches, including phantom imaging (全息影像) and oil painting, which are used to improve visitors' experiences. The exhibition shows four stages of the CPC from its establishment to its achievements.

Open: Tuesdays to Sundays 8:30-18:00 (closed on Mondays)

Former Site of the Editorial Department of New Youth

New Youth started the New Culture Movement and spread the influence of the May Fourth Movement. The site was briefly based in Beijing but moved back to Shanghai in 1920 and also served as the office for the Communist Party of China Central Committee in the 1920s.

Open: Thursdays to Tuesdays 9:00 - 11:30, 13:30 - 16:30 (closed on Wednesdays)

1. Where would visitors learn more about the history of the Red Army?

A．Jinggangshan.

B．Xibaipo.

C．The Nanhu Revolutionary Memorial Hall.

D．Former Site of the Editorial Department of New Youth.

2. What do we know about the Nanhu Revolutionary Memorial Hall?

A．It focuses on Chinese achievements in art.

B．It mainly advertises the coming anniversary.

C．It applies modernized methods to the exhibition.

D．It briefly introduces the rise and fall of Nanhu.

3. When can tourists visit Former Site of the Editorial Department of New Youth?

A．At 1:00 p.m. on Mondays.	B．At 9:00 a.m. on Wednesdays.
C．At 2:00 p.m. on Fridays.	D．At 5:00 p.m on Sundays.