Environment And Nature

Respuesta correcta: C) to treat used materials so they can be used again

• A) to use something again without throwing it awayIncorrect. That describes the general idea of reusing materials, but recycling means treating used material so it can be made into something new.
• B) to put rubbish in a bag for the collectorsIncorrect. Putting rubbish in a bag is disposal, the opposite of recycling, which keeps materials out of the rubbish.
• C) to treat used materials so they can be used againCorrect. Recycling means processing used material such as glass, metal or plastic so that it can be used again in new products.
• D) to make a river dirty with wasteIncorrect. Making a river dirty is polluting, which is the environmental problem that recycling tries to solve.

Respuesta correcta: C) reducing

• A) redoingIncorrect. "Redo" means to do something again, so it cannot mean making a quantity smaller.
• B) reusingIncorrect. "Reuse" means using a thing again, but it does not reduce how much new plastic you buy.
• C) reducingCorrect. "To reduce something" means to make it smaller or less, and it is the only option that fits "the amount of plastic you buy".
• D) recyclingIncorrect. Recycling refers to treating used material, while here the verb has to express buying less plastic in the first place.

Respuesta correcta: D) pollute

• A) pourIncorrect. "Pour" describes emptying a liquid out of a container, which is not what bottles do to a river.
• B) fillIncorrect. "Fill" only states a quantity, so it does not express the damage the bottles cause.
• C) coverIncorrect. "Cover" describes a surface, but it does not carry the idea of making water dirty.
• D) polluteCorrect. "To pollute" is the verb used when waste makes air, water or land dirty.

Respuesta correcta: C) Because forest clearing has reduced its habitat.

• A) Because it is hunted for its fur during the winter.Incorrect. Hunting for fur is never mentioned in the passage, so that detail is invented.
• B) Because the forest around Bogotá has many factories.Incorrect. The passage names no factories; the problem it describes is agricultural clearing of the forest.
• C) Because forest clearing has reduced its habitat.Correct. The text says farmers cleared forest to plant crops, so the bear survives in smaller fragments of its former range.
• D) Because it lives in cold regions far from the city.Incorrect. The cloud forest is close to Bogotá, and the passage never describes the bear's area as a cold region.

Respuesta correcta: B) has been reduced

• A) reducedIncorrect. The simple past "reduced" closes the process in the past, but the text says the reduction continues week after week.
• B) has been reducedCorrect. "Since" points from a past event to now, so the passive present perfect "has been reduced" is the required form.
• C) is reducingIncorrect. The passive of the present continuous would be "is being reduced"; "is reducing" cannot be used passively like this.
• D) reduces toIncorrect. "Reduces to" needs a final value after it, and it is not compatible with the ongoing meaning of "every week".

Respuesta correcta: D) desertification

• A) erosionIncorrect. Erosion is the wearing away of soil by water or wind; it is one step, not the final result described in the sentence.
• B) deforestationIncorrect. Deforestation is the loss of trees itself, but here the consequence for the land is the point of the sentence.
• C) pollutionIncorrect. Pollution refers to contamination by waste or chemicals, not to land turning into sand.
• D) desertificationCorrect. Desertification is the process by which dry land becomes desert because of the misuse of soil and vegetation.

Respuesta correcta: C) "The passenger pigeon is extinct because there are no individuals left in the world."

• A) "The spectacled bear is extinct because its forest has shrunk."Incorrect. The spectacled bear still lives in Colombia, so a shrinking habitat makes it endangered rather than extinct.
• B) "The Andean condor is extinct, although thousands still fly over the Andes."Incorrect. The sentence contradicts itself, because the condor still flies over the Andes, so it cannot be extinct.
• C) "The passenger pigeon is extinct because there are no individuals left in the world."Correct. "Extinct" means a species has disappeared completely, which is exactly the case of the passenger pigeon.
• D) "The blue whale is extinct; in fact, its population has grown recently."Incorrect. A species whose population grows is certainly not extinct, and the blue whale is a protected species.

Respuesta correcta: B) "We throw away about 300 bottles a day, and each one takes 450 years to break down, so sorting them is the only realistic option."

• A) "Bins are cheap, but nobody will use them here."Incorrect. It opens with a cost argument and then destroys it by claiming nobody will cooperate.
• B) "We throw away about 300 bottles a day, and each one takes 450 years to break down, so sorting them is the only realistic option."Correct. It quantifies the local problem, adds a scientific fact and then proposes the solution, which is the structure of a persuasive argument.
• C) "Recycling is a good idea; I am not sure about the details."Incorrect. "I am not sure about the details" shows no conviction, so it cannot persuade a group that has to take a decision.
• D) "Everyone should throw their rubbish in the river instead."Incorrect. Throwing rubbish in the river is pollution, so this argues against the proposal instead of for it.

Respuesta correcta: B) even though

• A) howeverIncorrect. "However" is an adverb, and as a connector it needs a full stop before it; here it would have to stand between the subject and the verb.
• B) even thoughCorrect. "Even though" introduces a concession between two true facts: high production and a low recycling rate.
• C) becauseIncorrect. "Because" makes the first clause the cause of the second, but the two facts are a contrast, not a cause and effect.
• D) otherwiseIncorrect. "Otherwise" expresses the consequence of not doing something, which is not the relationship described here.

Respuesta correcta: D) The national trend worsened while the Amazon trend improved.

• A) Total deforestation in Colombia decreased between 2010 and 2024.Incorrect. Because deforestation outside the Amazon rose, the national figure did not decrease; the improvement concerns one region only.
• B) Forests in the Colombian Amazon are no longer at risk.Incorrect. Losing 90,000 hectares a year is still a serious loss, so the text does not claim the Amazon is out of danger.
• C) The national trend improved and the Amazon trend improved as well.Incorrect. This reverses the information: the text says deforestation rose in the rest of the country while it fell in the Amazon.
• D) The national trend worsened while the Amazon trend improved.Correct. The Amazon lost less forest each year and the rest of the country lost more, so the two trends moved in opposite directions.

Respuesta correcta: A) ought to

• A) ought toCorrect. "Ought to" gives advice about future actions and takes the base form of the verb: ought to + build.
• B) oughtIncorrect. "Ought" on its own is not a complete structure for advice; it needs "to" before the verb.
• C) ought to builtIncorrect. "Ought to" is followed by the bare infinitive, never by the past participle.
• D) ought being toIncorrect. "Ought being to" mixes the continuous and the infinitive, which is not a form in English.

Respuesta correcta: A) Building platforms in trees can help a very rare species recover.

• A) Building platforms in trees can help a very rare species recover.Correct. The new chicks and the new sightings after the platforms were built support the conclusion that the intervention helped the species.
• B) The harpy eagle should be removed from the list of protected species.Incorrect. The text describes a recovery, which is precisely the situation in which protection is kept, not removed.
• C) Cloud forests are disappearing faster than any other habitat in Colombia.Incorrect. The text mentions the cloud forest only as the place where the eagle lives; it does not compare habitats.
• D) Chicks cannot survive in nests built above the ground.Incorrect. The text says nothing about ground nests, and in fact the chicks that hatched were raised in the elevated platforms.