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 Potala Palace (布达拉宫) features a wall painting     1     illustrates a historic marriage between members of the Han and Tibetan ethnic groups. Like the wall painting, many other relics in Tibet have also helped     2    (far) uncover cultural communication between Tibet and the rest of China.

    3    (original) built in the eighth century, the Samye Monastery is listed as an example of a combination of cultural heritage and architectural styles, while the Shalu Monastery, set up in 1087, is another example of a mix of architectural styles.

The earliest archaeological site     4    (identify) at the heart of the Qinghai-Tibet Plateau (高原) so far is the Nwya Devu site. More than 4,000 stone artifacts (石器)     5    (find) at the Paleolithic site since 2016. Scientific analysis shows that the site     6    (date) back to some 40,000 years ago.

Archaeological     7    (discovery) have also provided abundant evidence of cultural integration. For example, the wooden carving unearthed from Tibet’s Ngari and those from Xinjiang are similar     8     shape.

The cultural     9    (connect) between Tibet and the Yellow River basin was proved at the Karub ruins with the finding of a crop planted in northern China. The finding proved     10     communication between the plateau and northern China some 5,000 years ago.

2 . When it comes to planning a student trip, there are few better choices than our nation’s capital. There are many places of interest in Washington, DC, with sites that will attract students who are interested in everything from history, art, to STEM. Don’t miss these must-see sites on your trip to Washington, DC.

Smithsonian Museums

Managed by the Smithsonian Institution, admission (入场券) is free, and all locations are open every day except December 25. Students will love the exhibitions of the National Air and Space Museum, and everyone can enjoy the National Zoo, which is home to giant pandas, Sumatran tigers, and much more.

National Gallery (画廊) of Art

This is an amazing place for students interested in art. It includes the East Building and the West Building and houses the gallery’s more modern works and a collection of older works. The museum welcomes visitors from 10 am to 5 pm from Monday to Saturday and 11 am to 6 pm on Sundays. There is a variety of free self-guided and audio (音频) tours available.

Newseum

The Newseum aims to increase public awareness of the importance of a free press. Visitors can experience the story of news, the role of a free press in major events in history and how freedom of speech is applied to their lives.

Mount Vernon

Only 16 miles south of Washington, DC lies Mount Vernon, George Washington’s home. This historic place features beautiful gardens and wonderfully kept grounds. The outbuildings surrounding the main house still run today. Visitors can tour these structures in addition to the inside of the main house and go there by subway.

1. In Smithsonian Museums, students _________

A．are allowed to drive space ships

B．can get in close contact with nature

C．can watch animals and learn space knowledge

D．are free to visit the National Zoo at Christmas

2. What can we learn about the National Gallery of Art?

A．Students can enjoy famous artworks of different times there.

B．Some artists offer to teach visitors to draw for free

C．It just opens to the public from Monday to Saturday.

D．It helps visitors choose their favorite guide.

3. Which of the following may a George Washington fan prefer to visit?

A．Newseum.	B．Mount Vernon.
C．Smithsonian Museums.	D．National Gallery of Art.

3 . In April 2018, a group of Canadian scientists flying in a helicopter (直升飞机) discovered something they didn't expect to see — a huge, unknown cave with an opening the size of a football field.

The cave was discovered in the northern part of Wells Gray Provincial Park, in a wild, faraway area of Canada's Cariboo Mountains. The area is hard to get to and even harder to travel through. It is covered with snow for much of the year.   

The group told Catherine Hickson, a scientist who studies rocks, about the cave. Dr. Hickson got a team of researchers together to study it. In September, they went for a closer look after most of the snow melted (融化). The cave is one of the largest in Canada. Not only is the opening to the cave larger than a football field, the cave is also deep. The team couldn't measure (测量) all the way to the bottom, but they think it may be more than 180 meters deep. The cave is tens of thousands of years old. But the rock in the cave is made of used to be at the bottom of an ocean (海洋). It is hundreds of millions of years old.

A small, but fast river of melting snow leads into the cave on one side, creating a waterfall near the top and a river at the bottom. The water comes out again a long way away. The exit (出口) is about 2.1 kilometers away and about l/2 kilometer lower down.

The cave will have to wait to get an official name. For now, the cave is being called "Sarlacc's Pit "because it looks similar to the home of the Sarlacc, a person in the Star Wars movie Return of the Jedi.

For Dr. Hickson, there's a lesson to be learned from the cave. "It shows you that you don't know everything, "she says." There are things yet to be discovered."

1. Why did the cave remain unknown in the past?

A．It is in a wild mountain area.	B．It has been there for just a few years.
C．Its opening is too small to be noticed.	D．The weather there is cold all year round.

2. What are Paragraphs 4 and 5 mainly about?

A．The history of the cave.	B．Some facts about the cave.
C．The value of studying the cave.	D．The methods of studying the cave.

3. What does the underlined word "It" in Paragraph 4 refer to?

A．The snow.

B．The river.

C．The ocean.

D．The rock.

4. The cave's name "Sarlace's Pit" has something to do with ________.

A．local culture

B．its discoverers

C．the way it looks

D．the name of a film star