a. They had already left the village before the sun rose.
To form the past perfect tense, we use had + past participle. In this sentence, the past participle of "leave" is "left". The action of leaving the village happened before the action of the sun rising.
b. As soon as she finished cleaning the floors, she started gardening.
In this sentence, both actions happened in the past. The action of cleaning the floors happened first, indicated by the past simple tense "finished". Then, the action of starting gardening followed.
c. After posting the letter, I realized I had written the wrong address.
The action of posting the letter happened first, indicated by the past simple tense "posted". The action of realizing the mistake happened after, indicated by the past perfect tense "had written". The past participle of "write" is "written".
d. We had been driving for two hours when we saw the hotel.
The past perfect continuous tense is used to indicate an action that started in the past and continued up until another point in the past. In this sentence, the action of driving started before, indicated by the past perfect continuous tense "had been driving". The action of seeing the hotel happened later.
e. When I got home last night, my family had already gone to bed.
The action of getting home happened first, indicated by the past simple tense "got". The action of the family going to bed happened before, indicated by the past perfect tense "had gone". The past participle of "go" is "gone".
f. When I arrived home, I saw that someone had broken into my house.
The action of arriving home happened first, indicated by the past simple tense "arrived". The action of seeing the break-in happened after, indicated by the past perfect tense "had broken". The past participle of "break" is "broken".
g. They were watching TV when the earthquake occurred.
The past continuous tense is used to indicate an ongoing action that happened in the past. In this sentence, the action of watching TV was ongoing when the earthquake happened.
h. I looked out of the window last night because I heard some noises.
The action of hearing the noises happened first, indicated by the past simple tense "heard". The action of looking out of the window happened after, indicated by the past simple tense "looked".
1. Environmental protection is an important problem.
- Обоснование: Environmental protection is a significant issue because it involves safeguarding the natural world and ensuring its sustainability for future generations.
2. Factories pour a lot of pollution into the air and water.
- Обоснование: Factories release harmful substances into the air and water, causing pollution and damaging the environment.
3. Water is an important source for growing vegetables.
- Обоснование: Water is necessary for plants to grow. It provides them with hydration and carries essential nutrients to their roots.
4. Many rivers and lakes are polluted.
- Обоснование: Due to human activities, rivers and lakes often become contaminated with pollutants such as industrial waste, chemicals, and sewage.
5. Many scientists try to solve ecology problems.
- Обоснование: Scientists study ecological issues to understand the impacts of human activity on the environment and develop solutions to address these problems.
6. People must recycle aluminum cans and newspapers.
- Обоснование: Recycling helps to reduce waste and save valuable resources. Aluminum cans and newspapers can be recycled to conserve energy and raw materials.
7. Ecology is a science which studies the relationship between all forms of life on our planet and the environment.
- Обоснование: Ecology explores the intricate connections between living organisms and their physical surroundings, including how they interact and depend on each other.
8. Big cities suffer from smog.
- Обоснование: Smog is a type of air pollution that is often more prevalent in densely populated urban areas due to industrial emissions and vehicle exhaust.
9. Every ten minutes, one kind of animal, plant, or insect dies out forever.
- Обоснование: The loss of biodiversity is a major concern as different species become extinct due to habitat destruction, pollution, climate change, and other human activities.
10. The wide use of natural resources upsets the biological balance.
- Обоснование: Overexploitation and unsustainable use of natural resources can disrupt ecosystems, leading to imbalances in populations and negative ecological consequences.
11. Parents protect their children from harm.
- Обоснование: It is the responsibility of parents to safeguard their children's well-being and safety from potential dangers and risks.
12. Teacher's good influence made him better.
- Обоснование: A teacher's positive influence and guidance can contribute to personal growth and improvement in a student's academic performance and behavior.
13. People do their best to protect nature.
- Обоснование: Individuals make efforts to preserve nature by practicing environmentally friendly behaviors such as reducing waste, conserving energy, and supporting conservation initiatives.
14. The environment is natural conditions such as clean air, water, land, and others.
- Обоснование: The environment encompasses the physical surroundings that support life on Earth, including the air we breathe, the water we drink, the land we cultivate, and other essential elements.
15. The Earth is the source of our wealth.
- Обоснование: The Earth provides valuable resources and services that sustain human life and economic activities, making it the foundation of our wealth and well-being.
Choose the right words to go with «living things» and «non-living things»:
- Обоснование: Материалы должны быть разделены на две группы - живые существа (living things) и неживые предметы (non-living things).
16. living things: plant, organism, wolf, bird
17. non-living things: water, lake, salt, fly, river, mountain
Put the appropriate article where necessary:
- Обоснование: Необходимо определить, требуется ли ставить артикль перед существительными или нет. Выбранный артикль должен соответствовать контексту предложения.
18. People do their best to protect nature.
- Обоснование: Since the sentence talks about nature in general, "the" is not needed.
To form the past perfect tense, we use had + past participle. In this sentence, the past participle of "leave" is "left". The action of leaving the village happened before the action of the sun rising.
b. As soon as she finished cleaning the floors, she started gardening.
In this sentence, both actions happened in the past. The action of cleaning the floors happened first, indicated by the past simple tense "finished". Then, the action of starting gardening followed.
c. After posting the letter, I realized I had written the wrong address.
The action of posting the letter happened first, indicated by the past simple tense "posted". The action of realizing the mistake happened after, indicated by the past perfect tense "had written". The past participle of "write" is "written".
d. We had been driving for two hours when we saw the hotel.
The past perfect continuous tense is used to indicate an action that started in the past and continued up until another point in the past. In this sentence, the action of driving started before, indicated by the past perfect continuous tense "had been driving". The action of seeing the hotel happened later.
e. When I got home last night, my family had already gone to bed.
The action of getting home happened first, indicated by the past simple tense "got". The action of the family going to bed happened before, indicated by the past perfect tense "had gone". The past participle of "go" is "gone".
f. When I arrived home, I saw that someone had broken into my house.
The action of arriving home happened first, indicated by the past simple tense "arrived". The action of seeing the break-in happened after, indicated by the past perfect tense "had broken". The past participle of "break" is "broken".
g. They were watching TV when the earthquake occurred.
The past continuous tense is used to indicate an ongoing action that happened in the past. In this sentence, the action of watching TV was ongoing when the earthquake happened.
h. I looked out of the window last night because I heard some noises.
The action of hearing the noises happened first, indicated by the past simple tense "heard". The action of looking out of the window happened after, indicated by the past simple tense "looked".