6. After all the groups finish their reports, have students check their notes in their groups, or summarize other groups? findings.

I. Watch Part 1. Decide whether the following statements are true (T) or false (F). ____F__ This part focuses on the types of the Rocky Mountain locust. ____F__ Locusts exist on all continents.

____T__ An unbelievable event happened in 1875 when weather conditions helped to create the \

____T__ The \ caused extensive damage to the vegetation. ___F___ The worst storm disappeared in a few hours.

___T___ Locusts could hurt people physically and emotionally. II. Watch again. Fill in the blanks with the missing information.

This part is mainly about the history and the present situation of the Rocky Mountain locust in (1) North America. In the mid-1800s, thousands of pioneers journeyed across the U.S. in search of (2) free land and (3) new opportunities. They settled on the frontier of the western states, and began to (4) farm the land intensively. Then, in 1875, there was a disaster caused by the a huge swarm of locusts. (5) Trillions of insects came together over the state of Texas, and flew quickly across the frontier in (6) a huge destructive cloud that was nearly (7) 3,000 kilometers long. The locusts (8) eventually went as far west as the Rocky Mountains, destroying everything (9) wherever they went. However, today people can't see any locusts in North America because the Rocky Mountain locust simply (10) vanished.

III. Oral work. Work with your partner. Make an interview between a news reporter and a person who witnessed the perfect swarm. Ask and answer questions about the disaster. The witness should try to explain and act out what he or she had seen, heard and felt.

Useful expressions

What did you see? What did you hear?

What did you do? Why did you run back to your home? How did you feel? How about the other people? Locusts

coming down from the sky like hail; looking with hungry eyes; turning this way and that; blocking the sun; bringing darkness; claws digging into their skin and hung upon their clothing … People

screaming into their homes; hearing sharp cracks as the insects came underfoot … I. Watch part 2. Choose the true statements about the Rocky Mountain locust.

______ The Rocky Mountain locust died as a result of a tremendous series of earthquakes, tidal waves and forest fires.

____√__ The extinction of locusts remains a mystery in the history.

______ The reason why the Rocky Mountain locust became extinct is not something Dr. Jeff Lockwood is interested in.

___√___ There are few locust specimens and they are not in good condition. ___√___ Strong winds would sweep swarms of locusts high into the mountains.

______ Locusts suffered a long and slow death. ______ Locusts suffered a sudden demise.

____√__ The whole body of a locust is found in the ice.

II. Watch again. Answer the following questions in five words or less.

1. How many years has Dr. Jeff Lockwood spent on the mysterious phenomenon? Over a decade.

2. What did the extinction of the Rocky Mountain locust change? American history.

3. In what condition are the few locust specimens? They are often in bad condition.

4. How would locusts die in the Rocky Mountain? They would freeze to death.

5. Where did Dr. Lockwood find the locust specimen? On one of the steeper parts of the mountain.

III. Oral work. Explain to your partner the reasons why Dr. Jeff Lockwood leads his team to the Rocky Mountain. Use the information you've learned in this part and the expressions below. Useful expressions

very few locust specimens exist and they are in bad condition a body of evidence of the victim in its dying moments

what the life of the victim looked like when it was flourishing a major set of clues is locked up in the ice extracting DNA samples from specimens

specifying exactly what caused the extinction of the insects

I. Watch part 3. Put the following statements in the correct order. A. Extract DNA samples.

B. Ensure the locusts they have are the right species.

C. Take the locusts back to the laboratory to examine them more closely. D. Find signs that the locusts didn't die of old age.

E. Realize the importance of looking at the species at the time of its weakest link. F. Conclude there must be some other force leading to the sudden death. ( C )→( B )→( A )→( D )→( F )→( E ) II. Watch again. Fill in the blanks in the table with the missing words. How did they know they had the Rocky Mountain locust? How do the locusts generally behave?

What do the locusts look like when they are annoyed?

What happens to their wings and legs when they are angry? What fact does the DNA test indicate? It was an exact match.

They're generally shy and remain alone.

They change completely into some kind of destructive monster. They grow longer.

They didn't decline over a long period of time.

III. Listen and repeat. You are going to hear five sentences selected from the video.

Repeat each sentence after it is spoken twice. Then write the sentences.

1. To get my hands on the body, in terms of this murder mystery, was critically important.

2. They are the same species of locusts that once devastated the American plains. 3. Eventually, they become more aggressive and swarm, whereby they become a kind

of living, breathing weapon of mass destruction. 4. There?s nothing in the genetic course of this species that would lead us to believe

that it was in its last days. 5. Some other force must have been responsible for destroying the plague. I. Watch part 4. Choose the best answer to each of the following questions. 1. Where did the Rocky Mountain locust lay its eggs?

A. In the forest of the mountains. B. On the top of the mountains.

C. In the river valleys of the mountains. D. In the farm land near the mountains.

2. Which of the following is NOT mentioned as being prosperous in the late 1800s? A. Silver industry. B. Coal industry. C. Gold industry. D. Agriculture.

3. Who was mainly responsible for the extinction of the Rocky Mountain locust? A. The farmers. B. The miners. C. Locusts themselves. D. The government. 1.A 2.B 3.A

II. Watch again. Complete the following sentences with the missing words.

1. Now, after years of research, Lockwood may finally be able to solve the mystery of why the Rocky Mountain locust disappeared.

2. The major nesting area of the Rocky Mountain locust had become a busy and overcrowded place.

3. By not allowing the eggs to mature into full-grown locusts, the species was entirely destroyed at its weakest when the insects were just eggs.

III. Oral work. Describe to your partner the exact reason for the extinction of the Rocky Mountain locust. Then explain your feelings or make comments on this incident in American agricultural history. Useful expressions

gather in one particular region gold and silver industries the pioneer agriculturalist of the Rocky Mountain West feed the miners plow up the fields

stamp out the delicate eggs What a pity it is! That's too bad! It's just an accident. No one should be blamed …

I. Watch the entire video. Choose the appropriate heading for each part.

Part 1 ___B___ A. Dr. Lockwood finds the Real Cause of the Rocky Mountain Locust Extinction

Part 2 ____C__ B. The Unthinkable Event in North America in the 1800s Part 3 ____D__ C. Dr. Lockwood's Confusion about the Cause of the Extinction

Part 4 ____A__ D. Dr. Lockwood's Analysis and Introduction to Some Locust Facts

II. Oral work. Work with a partner. Describe the picture below. Use the information from the video and the expressions below. Useful expressions

thousands of pioneers journeyed west

across the U.S. in their covered horse-drawn wagons in search of free land wide open spaces

new opportunities with their great expectation about their future life …

III. Project. Form groups of three or four. Each group does research online or in the library on a kind of insect. Then each group fills in the following table and reports the findings to the whole class.

Insects grasshopper butterfly dragonfly cricket bee moth beetle How many types are there? What does it look like? Where does it live? What does it live on? What can it do?

What benefits or harms does it bring to human beings? READING

The Perfect Swarm

1 In parts of the world, such as West Africa, the damage from the swarms of locusts that can plague an area often reach disastrous proportions. At times, countries are attacked by billions of locusts, which can easily invade entire regions, greedily eating everything in sight. A single swarm of desert locusts can consume over 70,000 metric tons of vegetation a day, enough to feed 200 million people.

2 Locusts are one of the world's most destructive insects, and for some, they bring to mind images of terror and destruction. These seemingly harmless insects can have a devastating effect on a country's food reserves when appearing in large numbers. These disaster-causing insects can live almost everywhere in the world so they affect a large number of people; however, there is one continent where locusts don't exist at all.

3 At the present time, North America is the only continent on Earth that isn't home to the locust but, interestingly enough, this wasn't always true. For hundreds of years, the Rocky Mountain locust was a very common pest in the American West, causing massive destruction to crops and costly disturbances to agricultural economies. However, in the late 1800s, an extremely odd phenomenon occurred involving the Rocky Mountain locust. It's a case that has been recorded several times in history by people who witnessed it, and without documentation, the event would seem almost unreal.

4 Back in the mid-1800s, thousands of pioneers journeyed west across the U.S. in their covered horse-drawn wagons in search of free land, wide open spaces, and new opportunities. They settled on the frontier of the western states, and began to farm the land intensively, growing corn and other crops. They struggled to earn a living from the soil and worked for days on end to break the earth into farmable fields using only