Unit 4 The Wonders of Nature 自主检测 2025-2026学年人教版八年级英语下册

Unit 4   The Wonders of Nature 自主检测

Ⅰ.完形填空(每小题1分，共15分)

Clouds often appear in the  1   , but do you really stop to  2  at them? Do you wonder about their names? The activity is called cloud spotting (观云).

Ji Yun, born in 1987, is a cloud spotter in Beijing. He enjoys  3  about them, such as knowing their names according to their  4

Ji loves  5  deeply. He began to find out more about the beauty of clouds after taking some photos of an ice ha lo (冰晕 ). “I can't stop myself from  6  them,” said Ji.

In October 2013, Ji got a(n) 7  from a friend. There were very  8  asperitas clouds(糙面云 ) in Beijing, and they were quickly going southeast. “ 9  I got the information, I rushed out of my home,” Ji said.  10  a second thought, he took a high-speed train to Tianjin. At that time, the trains weren't as  11  as today's.In the end, he  12  took photos of the clouds in Tianjin’ s Wuqing area. The cloud was one of the world's  13  10 rarest (罕见的) clouds.

Ji’ s story made  14  popular. Around that time, he created some online groups to  15 the same love for clouds with fans. He said, “Can a cloud or an evening sky make you stop and look up? If yes, please join us.”

1. A. land B. sky C. ocean D. desert

2. A. look into B. look for

C. look up D. look down

3. A. learning B. bringing

C. talking D. worrying

4. A. seasons B. time

C. sizes D. shapes

5. A. nature B. music

C. sport D. art

6. A. feeling B. discussing

C. researching D. seeing

7. A. notice B. advice

C. opinion D. message

8. A. dark B. special

C. normal D. terrible

9. A. Before B. Until

C. Unless D. As soon as

10. A. With B. Without

C. At D. In

11. A. big B. long

C. few D.common

12. A. quickly B. successfully

C. carefully D. easily

13. A. famous B. beautiful

C. top D. nice

14. A. him B. her C. you D. them

15. A. send B. tell C. write D. share

Ⅱ.阅读理解(每小题2分，共16分)

A

The Amazon is one of the world's longest rivers,  second  only  to  the  Nile  in  Africa.Beginning from the Andes Mountains in Peru, the Amazon runs  4,000  miles  eastward  through Colombia and Brazil to the Atlantic Ocean. The river is usually about one to six miles wide.During the rainy season, it can be as much as 20miles wide in some areas. It is also one of the deepest rivers, reaching 300 feet deep in a number of areas.

The river is also important because it runs through the Amazon rain forest. Home to some of the planet's most amazing and unusual birds, fish,insects, and animals, the Amazon rain forest has the most plant and animal species ( 物种) in the world. Brightly colored parrots, monkeys, and frogs live here. In the water, you' ll find pink dolphins. Some of the plants and trees in the rain forest have been used as medicines for thousands of years.

The river became known as the Amazon during the mid-1500s. A Spanish man (西班牙人) saw some women fighters along its lower banks and named the river after them. In Greek mythology (神话), the Amazons were a group of women who were very good at fighting.

16. Which country does the Amazon run through?

A. Brazil. B. India.

C. South Africa. D. France.

17. What does“Amazon” mean according to the last paragraph?

A. A Spanish man. B. A long river.

C. A rain forest. D. A woman fighter.

18. What can be the best title for the passage?

A. The Amazon

B. The Amazon Rain Forest

C. The Animals in the Amazon

D. The Story about the Amazon

B

A blue hole is a flooded sea cave (洞穴)with a hole that opens up at the land's surface.These cave systems form in carbonate rock, often on islands. Far below sea level there are some of the hardest environments  on Earth,  with no oxygen ( 氧) and no light. Yet these areas are filled with life forms that have got used to such conditions.

Blue holes get their name from the color that some have when seen from the air. It is usually a reflection of the sky on the water.    ★  Some have dark or muddy water.

Blue holes have several layers of water,chemicals and bacteria (细菌). The top layer of fresh water comes from rainfall, which acts like a cap on top of the layered mixture and keeps out oxygen from the air. The fresh water covers a denser layer of salt water. Underneath this is a layer of poisonous hydrogen sulfide (有毒的硫化氢), produced by bacteria living in the water. At the bottom is anoxic seawater— water that does not have any oxygen.

“Underwater caves are probably one of the least understood  ecosystems  on  the  planet,”Kenny Broad, a scientist at the University of Miami in Florida, says. “One reason is that you still physically have to go there— you can't send in a submarine (潜水艇) or any other machine.”

There are many safety rules that divers must follow to help ensure their survival. First, divers must have training to swim in such caves. Those who explore an underwater cave for the first time must use a thin rope called a guideline, which helps them to safely enter and exit without getting lost. Besides,  divers must bring several light sources and more than one set  of breathing equipment (设备) just in case. And they must pay careful attention to their air supply (供应).

19.According  to  the  passage,  blue holes                 .

① are sea caves far below sea level

② give off bright blue light

③ h ave life forms but no oxygen and light

④ are found mostly on islands

⑤ include three layers in all

A.①②⑤ B.②③④