Đáp án+Giải thích các bước giải:

 Điều kiện:`x-2m+4>=0<=>2m<=x+4`

`(x-5\sqrt{x}+6)\sqrt{x-2m+4}=0`

`<=>(x-2\sqrt{x}-3\sqrt{x}+6)\sqrt{x-2m+4}=0`

`<=>(\sqrt{x}-2)(\sqrt{x}-3)\sqrt{x-2m+4}=0`

Để phương trình có đúng 2 nghiệm phân biệt

`<=>4+4<=2m<9+4`

`<=>8<=2m<13`

`<=>4<=m<13/2=6,5`

Mà `m\in ZZ<=>m\in {4;5;6}(tmdk:m\in[-1;10])`

A. PHONETICS

I. Find the word which has a different sound in the part underlined.

1.

A. government

B. borrowing

C. program

D. promotion

2.

A. polar

B. land

C. impact

D. animal

3.

A. possession

B. access

C. property

D. American

4.

A. release

B. easy

C. threat

D. increase

5.

A. preserve

B. conserve

C. fossil

D. discuss

Choose the word which has a different stress pattern from the others.

1.

A. protection

B. charity

C. chemical

D. neighbourhood

2.

A. submarine

B. assignment

C. disposal

D. depletion

3.

A. chemical

B. solution

C. disposal

D. erosion

4.

A. scientist

B. chemical

C. injury

D. announcement

5.

A. evidence

B. principle

C. allergy

D. awareness

B. VOCABUALRY AND GRAMMAR

I. Change into the reported speech.

1. He said “I have already read this book”.

    He said that he had already read that book.

1. Tom said to his sister “I want to buy a gift for our mother”.

    Tom told his sister that he wanted to buy a gift for thier mother.                                       

1. Mrs Brown said “Where are they living?”

    Mrs Brown asked where they were living.

1. “Do you know the girl over there?” Tom said.

    Tom asked me if I knew the girl over there.

1. Mother said “Nam, why don’t you go to bed?”

    Mother told Nam not to go to bed.

1. “May I use your telephone?” said my neighbor.

    My neighbor asked me to use my telephone.

1. The manager said “Come into my office, please?

    The manager asked to come in to his office.

1. “Do not get off the bus while it’s going” said the driver.

    The driver asked us not to get off the bus while it was going.

1. She asked to the little boy “Take a look at yourself in the mirror!”

    She told the little boy to take a look at himself in the mirror.

1. “Don’t put your elbow on the table!” he said.

      He asked me not to put my elbow on the table.

II. Put the correct word for the sentences below.

deforestationpreservegreenhouse effectfossil fuelsdamagedepletionpolluteglobal warming

1. The ____ greenhouse effect _____ occurs when the earth’s atmosphere traps certain gases such as carbon dioxide as well as water vapour. This makes the earth’s surface warmer.
2. ______Damage________ is harm or injury that makes something less valuable or able to function.
3. To ______ preserve ________ is to keep and protect something from damage, change or waste.
4. ____ Fossil fuels ______ are non-renewable energy sources such as coal, fuel oil and natural gas formed from dead plants and animals underground.
5. ___ Global warming ____ is the gradual increase of temperature on the earth’s surface due to greenhouse effect.
6. ______ Depletion ______ is the using up or reducing something like energy or resources.
7. To _____pollute_______ is to make air, water, or soil dirty or unclean.
8. ____ Deforestation _____ is the removal or cutting down of all trees in an area for urban use and farm lands.

III. Choose the correct words in the bracket to complete the sentences.

preservedforestationconfusederosionglobalenvironmentattractionenvironmental

1. Scientists have tried to assess the impact of human activities on the ______ environment ______.
2. We should have ____ forestation ____ plans to replace the trees cut down for farmland use in the region.
3. Oceanic oil spills become a major ____ environmental _____ problem, chiefly a result of intensified petroleum exploitation.
4. The rhino habitat has been perfectly _____ preserved _____ in the region.
5. The students are somewhat ____ confused ___ by the usage of the words “preservation” and “conservation”.
6. Many climatologists believe that the decline in mountain glaciers is one of the first observation signs of _____global____ warming.
7. Rising sea levels can add to the _____ erosion _______ of our coastlines.
8. Waste water has polluted seas and lakes surrounding tourist ____ attraction _____, damaging the flora and fauna.

IV. Use the word given in capitals at the end of each line to form a word that fits in the gap in the same line.

1. In banana plantations, flooding occurs partly because of  deforestation and partly because of poorly ____constructed____ drainage systems.

2. African and Asian elephant numbers feel dramatically in the 19^th and 20^th centuries, ___largely_____ due to the ivory trade and habitat loss.

3. The environmental consequences of large dams are numerous, including direct impacts to the biological, chemical and _____physical______ properties of rivers.

4. In areas with high concentrations of tourist activities and attractive natural attractions, waste ______disposal______ is a serious problem.

5. Unlike pesticides, ______fertilizers_____ are not directly toxic but their presence in fresh water changes the nutrient system.

6. ___Erosion_____ caused by deforestation can also lead to increased flooding.

7. The Earth’s natural resources should be consumed at a ____sustainable___

level.

8. Dealing with resource _____depletion______ requires a broad range of strategies.

9. Experts predict that the world’s rain forests could completely disappear in 100 years at the current rate of ____deforestation_____.

10. Mining is an extractive industry, often with huge ____environmental____

and social impacts.

CONSTRUCT

LARGE

PHYSICS

DISPOSE

FERTILIZE

ERODE

SUSTAIN

DEPLETE

DEFOREST

ENVIRONMENT

V. Choose the best answer A, B, C or D to complete the sentences.

1. Jack asked me ____.

A. where do you come from?

B. where I came from

C. where I come from

D. where did I come from?

2. She asked me ____ I liked pop music.

A. when

B. what

C. if

D. x

3. The doctor ____ him to take more exercise.

A. told

B. tell

C. have told

D. are telling

4. I wanted to know ____ return home.

A. when would she

B. when will she

C. when she will

D. when she would

5. Claire told me that her father ____ a race horse.

A. owns

B. owned

C. owning

D. A and B

6. What did that man say ____?

A. at you

B. for you

C. to you                    

D. you

7. I rang my friend in Australia yesterday, and she said it ____ raining there.

A. is

B. were

C. has been

D. was

8. The builders have ____ that everything will be ready on time.

A. promised

B. promise

C. promises

D. promising

9. The doctor ____ him to take more exercise.

A. told

B. tell

C. have told

D. are telling

10. The last time I saw Linda, she looked very relaxed. She explained she’d been on holiday the ____ week.

A. ago

B. following

C. next

D. previous

11. Fossil fuels which are non-renewable pollute the air and cause air ____.

A. pollution

B. solution

C. contaminate

D. consumption

12. Recycling provides a method of reducing the amount of waste materials that gets to the landfills – thus ____ it less probable for environmental pollution to take place.

A. making

B. doing

C. causing

D. trying

13. If wastes are thrown ____, they can cause pollution in water, land and air.

A. inappropriately

B. disappointingly

C. eco-friendly

D. favourably

14. Trees not only bring nature to urban areas, but they also help clean the air by absorbing pollutants, ____ oxygen, ____ water, and grow food.

A. to provide – to save

B. to provide – save

C. providing – saving

D. provide – save

15. Air pollution is such a serious ____ that it has been a direct factor in the ____ of millions of people each year.

A. threat – death

B. threat – deaths

C. threaten – death

D. threaten – deaths

16. Sometimes it’s better not to buy something new, and buy it ____ instead.

A. used

B. usable

C. use

D. useful

17. He asked the children ____ the river.

A. don’t pollute

B. if they don’t pollute

C. not to pollute         

D. not polluting

18. They asked me how many students ____ in the school.

A. there were

B. were there

C . there are

D. are there

19. He told me that ____.

A. he would participate in the conservation campaign yesterday

B. he had participated in the conservation campaign the previous day

C. he participated in the conservation campaign the previous day

D. he has participated in the conservation campaign the previous day

20. He asked, “Why did she write the article on conservation?”

He asked why  ____.

A. she had written the article on conservation

B. she has written the article on conservation

C. she wrote the article on conservation

D. did she write the article on conservation

VI. Identify the one underlined word or phrase that must be changed to make the sentence correct.

1. The (A) deplete of the ozone layer (B) is not (C) a good thing (D) for the Earth. → depletion
2. We (A) need (B) to protect the (C) environmental for the (D) next generation. → environment
3. Deforestation will lead (A) to the extinction of rare (B) animal due to the loss of (C) their habitats, and (D) extreme floods and land erosion. → animals
4. (A) Worldwide rainforest (B) preserve has (C) been the aim (D) of many environmentalists. → preservation
5. (A) Person should (B) make efforts to preserve the environment (C) for the sake of (D) themselves and their children. → People
6. Environmental (A) pollute is (B) one of the greatest and most urgent (C) problems in modern (D) times. → pollution
7. Many countries (A) have signed up to international agreements (B) which aim (C) to reduce the negative (D) impaction of climate change. → impact
8. (A) Any amateur (B) gardener knows (C) plantation need two things (D) to survive: sunlight and water. → plants

C. READING

I. Fill each of the numbered blanks in the following passage. Use only one word in each space.

homebalancewaywarmingforestsecosystemsvalueofamountlife

PROTECTING BIODIVERSITY

Protecting biodiversity is now very essential since biodiversity is crucial for reducing climate pollution. If we don’t protect biodiversity, the effects could be as harmful as the effects of global (1) ____warming____ itself. This is especially true with tropical (2) ____forests_____ – they are critical to fighting climate change and (3) ____home___ to more species than any other ecosystem type. In other words, protecting biodiversity is essential for our well-being, and biodiversity helps to (4) _____balance______ the nature.

Biodiversity is an important part of sustainable development. As we know, sustainable development is considered as a major target for industry as well as planning system. However, the only (5) ____way_____ to achieve this target is to protect biodiversity. Tiny plants that grow also absorb large (6) ____amount_____ of carbon dioxide. That is why protecting diversity is essential.

In fact, biodiversity protection is very much important since biodiversity is a fundamental component of (7) ___life____ on Earth. It creates complex (8) ____ecosystems____ that could never be reproduced by humans. The (9) ___value__ of that biodiversity is immeasurable, and thus must be protected. Finally, we both want and need biodiversity. We continue harming the natural environment without realizing the impact. We should be aware (10) ____of___ protecting biodiversity.

II. Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage.

World Environment Day which is (1) ____ on 5^th June every year in an important day in the calendar of the United Nations. It is one of the ways the United Nations uses to advocate for environmental (2) ____ and call for political action.

Every year, UNEP (the Environment Program of the United Nations) develops a theme which is used globally to raise (3) ____ and call for support from governments, organizations, and individuals from all over the world.

The theme for 2015 was “Seven Billion Dreams. One Planet. Consume with Care”. This would also serve as the slogan for the World Environmental Day 2015. The meeting of this theme and slogan is that we have five (4) ____ with more than seven billion people combined. Although we have about 7 billion people, we just have one planet that we live and survive. The surface area is limited, shelter and food also limited. If we continue using the available natural (5) ____ as we do today, our future generations may be (6) ____ to go hungry and without homes. This is why it is of vital importance to consume (7) ____food that is available with care. Stop the wastage and use whatever resource that is available according to need, not greed.

“Join the race to make the world a better place” is the theme and (8) ____ for 2016 UN World Environment Day. This slogan (9) ____ a clear message and asks everyone to get involved (10) ____ making the world a better place to live in.

1.

A. found

B. acted

C. held

D. celebrated

2.

A. experience

B. protection

C. decrease

D. pollution

3.

A. feature

B. activity

C. ability

D. awareness

4.

A. areas

B. continents

C. plants

D. stars

5.

A. sources

B. resources

C. balances

D. increase

6.

A. had

B. made

C. forced

D. accused

7.

A. which

B. whatever

C. who

D. what

8.

A. slogan

B. flag

C. poster

D. brand

9.

A. requests

B. asks

C. carries

D. depends

10.

A. from

B. to

C. within

D. in

D. WRITING

I. Change into the reported speech.

1. Mr Jones gave the people gloves and said to them: “Protect yourselves from germs.”

    Mr Jones gave the people gloves and told them to protect themselves from germs.

1. Nam said, “The environment is severely affected by pollution.”

    Nam said (that) the environment was severely affected by pollution.

1. Mai said, “The burning of fossil fuels leads to air pollution.”

    Mai said (that) the burning of fossil fuels led to air pollution.

1. Peter said, “Intensive insecticide and pesticide sprays in agriculture make the soil contaminated.”

    Peter said (that) intensive insecticide and pesticide sprays in agriculture make the soil contaminated.

1. “It’s confusing because there are too many web pages about the environment” Nam said.

    Nam said that it was confusing because there were too many web pages about the environment.

1. “Air pollution is one of the causes of the greenhouse effect” scientists said.

    Scientists said that air pollution was one of the causes of the greenhouse effect.

1. “Pollution is one of the problems in my neighbourhood” Nam said.

    Nam said that pollution was one of the problems in his neighbourhood.

1. “More people are aware of the preservation of natural resources” the editor said.

    The editor said that more people were aware of the preservation of natural resources.

1. “We are discussing the protection of the natural environment” the students told their teacher.

    The students told their teacher that they were discussing the protection of the natural environment.

1. “Use the web search engine to find the information that you need” Nam’s father told him.

      Nam’s father told him to use the web search engine to find the information that he needed.

II. Change into the reported speech.

1. Mr Jones was very sad and said “All this rubbish is killing fish and other sea creatures.”

    Mr Jones was very sad and said that all that rubbish was killing fish and other sea creatures.

1. “We can clean the beach together.” said Nick.

    Nick said that they could clean the beach together.

1. “I’ll ask our friends and neighbours to come and help us” Mary said to them.

    Mary told them that she would ask their friends and neighbours to come and help them.

1. “I’m so happy to hear that, children” Mr Jones said to his children.

    Mr Jones told his children that he was so happy to hear that.

1. Tony said “The disposal of untreated sewage in rivers and oceans leads to water pollution.”

    Tony said (that) the disposal of untreated sewage in rivers and oceans led to water pollution.

1. Mary said “Loud and annoying sounds from innumerable vehicles in the highway nearby cause noise pollution.”

    Mary said (that) loud and annoying sounds from innumerable vehicles in the highway nearby cause noise pollution.

1. Mai said “The rising sea level is product of global warming, a natural phenomenon. The only unnatural thing about global warming is the accelerated rate at which it is happening.”

    Mai said (that) the rising sea level was product of global warming, a natural phenomenon. The only unnatural thing about global warming was the accelerated rate at which it was happening.

1. Linda said “Environmental pollution is an impact of human activities on the environment.”

    Linda said (that) environmental pollution was an impact of human activities on the environment.