Scientific Innovations

Respuesta correcta: D) exacerbate

• A) alleviateIncorrect. 'Alleviate' means to make something less severe, which is the opposite of what's needed.
• B) mitigateIncorrect. 'Mitigate' means to make something less severe, which doesn't fit the negative consequence implied.
• C) facilitateIncorrect. 'Facilitate' means to make an action or process easy or easier, which is not appropriate for a social divide.
• D) exacerbateCorrect. 'Exacerbate' means to make a problem or bad situation worse, which fits perfectly here.

Respuesta correcta: B) discard

• A) retain'To retain' is to keep something, the direct opposite of what the sentence describes. If the team had kept the procedure, there would be no reason to start again from the ground up.
• B) discard'To discard something is to throw it away as worthless. Inconsistent results mean the procedure cannot be trusted, and building the apparatus again is exactly what happens when the earlier version is discarded and replaced.
• C) refine'To refine' is to improve something that already works by making small adjustments. Inconsistent results are not a flaw to polish; they show the method is fundamentally unsound and has to be replaced.
• D) postpone'To postpone' is to delay something to a later time. The sentence says the team started the work over immediately, which is the opposite of putting it off for another date.

Respuesta correcta: C) undermines

• A) corroborates'Corroborate' means to confirm with supporting evidence, and a method untested elsewhere supplies no such confirmation. The sentence describes the opposite effect on the field's confidence.
• B) anticipates'Anticipate' means to expect something in advance, and the sentence concerns confidence in results already published. Nothing here concerns a prediction about future work.
• C) undermines'Undermine' means to weaken something that was relied upon, and results nobody has independently reproduced leave every later claim resting on an unverified base. The clause names what is lost as a direct consequence.
• D) quantifies'Quantify' means to express something as a quantity, and the clause is about trust rather than measurement. The problem described is epistemic, not numerical.

Respuesta correcta: A) attribute

• A) attribute'To attribute an effect to a change is to assign the cause. When two experiments differ in only one controlled way, that variable is the one the result can be attributed to, and the reviewers are saying the design no longer allows it.
• B) deny'To deny' is to refuse to admit that something exists, which is not what a variable being untraceable means. The problem is that the effect cannot be traced to a cause, not that anyone is refusing to acknowledge it.
• C) accelerate'Accelerate' concerns speed, and the sentence raises a problem of design rather than of timing. Nothing in it suggests the experiments were fast or slow, only that too many variables changed at once.
• D) celebrate'Celebrate' marks a success, and the reviewers are issuing a warning. The complaint is that a crowded control scheme destroys the ability to isolate the cause, which is a drawback rather than an achievement.

Respuesta correcta: C) A biological method that has helped reduce dengue in Medellín and Bello.

• A) Why dengue cases increased in Medellín.The text reports a drop in dengue cases in the treated areas, not an increase.
• B) How chemicals are used to kill mosquitoes.The text says the method 'does not use chemicals'.
• C) A biological method that has helped reduce dengue in Medellín and Bello.The text explains the method (mosquitoes with a natural bacterium), its result (fewer dengue cases) and its expansion to other cities.
• D) A new vaccine against dengue tested in Bello.The method uses mosquitoes and bacteria, not a vaccine given to people.

Respuesta correcta: D) Each one closes a different loophole that had made earlier findings unreliable.

• A) The three labels together mean the findings have already been proven beyond any doubt.No set of labels removes uncertainty from a result. Peer review, open data and pre-registration make a study checkable; they do not convert a finding into absolute proof, and the report does not claim that they do.
• B) The lab wanted to attract more students to its graduate programme.Nothing in the sentence mentions recruitment or enrolment. The three labels are all about the reliability of evidence, which is a scholarly concern rather than an admissions one.
• C) The three labels are the minimum required for the results to be published anywhere.The report does not state a publication requirement. The phrase 'insist on all three' signals a methodological standard the lab holds itself to, not a rule imposed by a journal or an editor.
• D) Each one closes a different loophole that had made earlier findings unreliable.Peer review means independent experts checked the method, open access means anyone can inspect the data, and pre-registration means the hypothesis was fixed before the results appeared. Together they attack three separate ways a result can be misleading, and that is why all three are listed.

Respuesta correcta: B) It was usually considered waste with no commercial value.

• A) It was the most valuable part of the coffee fruit.Farms threw the pulp away, so it was not considered valuable.
• B) It was usually considered waste with no commercial value.Farms 'throw away tons' of pulp and even 'paid to get rid of' it, which shows it was treated as waste before the flour was invented.
• C) It was already sold to bakeries in Manizales.Bakeries use the pulp 'now', after the researchers' discovery, not before.
• D) It was used to make coffee stronger.The text does not mention any use of the pulp in the coffee drink.

Respuesta correcta: D) strong and able to survive difficult conditions

• A) expensiveThe seeds will be shared 'at low cost', so the text does not suggest that the variety is expensive.
• B) difficult to growThe variety produced good harvests in difficult conditions, which shows it is easy to grow, not difficult.
• C) fast-growingThe text says nothing about how fast the rice grows; it focuses on surviving floods.
• D) strong and able to survive difficult conditionsThe rice 'can survive several days under water' and produced good harvests 'even after heavy rains', which describes a hardy, resistant plant.

Respuesta correcta: A) That a Colombian university could design and operate a space project.

• A) That a Colombian university could design and operate a space project.The text states that 'it showed that a Colombian university could design, build and operate a space project'.
• B) That Colombia could send astronauts into space.Libertad 1 was a ten-centimetre cube that sent signals; no astronauts are mentioned.
• C) That large satellites are cheaper than small ones.The text does not compare prices, and Libertad 1 was a small satellite.
• D) That radio stations could build satellites.Radio stations only received the signals; the satellite was built by a university.

Respuesta correcta: A) Scientific progress can outrun the manufacturing capacity needed to turn discoveries into usable hardware.

• A) Scientific progress can outrun the manufacturing capacity needed to turn discoveries into usable hardware.The compound 'nobody fully understands' attaches to the supply chain, and the sentence moves from a paper to a device. The claim is that laboratory success is not the same as industrial capability: the components, fabs and logistics behind a prototype remain an unsolved dependency.
• B) The papers in this field are usually written by people who work outside universities.Nothing in the sentence concerns the authors' affiliations. The difficulty named is the supply chain behind the hardware, which is a matter of production rather than of who writes the research.
• C) Quantum computers have already been installed in Bucaramanga but are not being used well.The clause 'no breakthrough has yet moved from a paper to a working device' denies that any installed device exists. The report is describing a gap that has not yet been closed, not a machine that is present and neglected.
• D) Funding for quantum research in the region has been reduced in recent years.No budget or funding decision appears in the sentence. The obstacle described is technical and industrial, and inferring a cut in funding would go well beyond what the text states.

Respuesta correcta: C) self-consistent

• A) self-secure'Self-secure' is not an established compound in this sense, since security is not something a person or an explanation is secure with in the way the blank requires. The word does not combine with 'explanation' to convey consistency.
• B) self-concealing'Self-concealing' would describe something that hides itself, and the sentence is about internal agreement rather than concealment. Nothing in the clause suggests the team suspects the data of hiding anything.
• C) self-consistent'Self-consistent' means that its parts agree with one another, which is what an explanation must be to be worth proposing. The clause about no reading holding up under repetition describes the absence of that internal agreement.
• D) self-confident'Self-confident' applies to a person or a manner, not to an explanation's internal logic. The clause is about an account that coheres or fails to, which is a different property entirely.

Respuesta correcta: C) precondition

• A) preconditioning'Preconditioning' names an act of preparing something, and an appositive here needs a noun rather than a gerund. The trailing relative clause refers to a thing, not to an activity anyone performed.
• B) preconception'Preconception' means a belief formed in advance, and the clause is about a temperature the laboratories had to maintain. The two words share a prefix but belong to unrelated senses, which is the trap this option sets.
• C) preconditionA precondition is a condition that must be satisfied before the process can proceed, which is what the trailing 'that' clause describes as binding on every laboratory. 'A precondition' is also a natural appositive after a comma.
• D) precedent'Precedent' means an earlier case used as a model, and no such case appears in the sentence. The temperature is being described as binding on the trial, not as following a prior example.

Respuesta correcta: B) replicate

• A) replicate theA determiner cannot stand alone as the blank, since the verb already has its complement to hold. 'Replicate' needs a noun or a gerund after it, and no noun is supplied in this sentence.
• B) replicate'Replicate' is what a reader has to do with a finding to check it, and the notebooks are precisely what would make that possible. The gerund form 'replicating' is also the only one of the options that fits the verb pattern.
• C) replicated'Replicated' is the past participle, which cannot act as the bare verb before a gerund. The structure requires an infinitive, since 'hard to' governs that form directly.
• D) replicating itA personal pronoun cannot appear as the object of a gerund used in this way, since the gerund already functions as the object of the sentence. Adding 'it' would leave the clause without a verb.

Respuesta correcta: B) does

• A) do'Do' is the plural auxiliary, but the subject 'a replication attempt' is singular. The auxiliary has to agree with the subject it precedes, and a singular subject takes 'does'.
• B) does'Rarely' in front of a main clause triggers inversion, and 'does' is the auxiliary that carries the present tense here: 'rarely does a replication attempt succeed'. The lexical verb 'succeed' stays in its base form because the auxiliary already carries the tense.
• C) has'Has' would form a perfect and would need the past participle 'succeeded'. The sentence describes what happens whenever replication is attempted, which is a general present fact rather than a completed event.
• D) will'Will' sets the action in the future, but the clause opens with 'Rarely' and states a recurring condition of the present. Nothing in the sentence predicts a future event.

Respuesta correcta: A) handling

• A) handling'Data-handling' names the treatment of data, which is exactly what the clause describes a reader needs to know in advance. The hyphen and the attributive position before 'statement' are both correct for a compound of this kind.
• B) handle'Handle' is a verb and would leave the compound incomplete, since 'data-handle' names nothing. The blank has to supply a noun, because 'statement' needs a modifier rather than an action.
• C) handled'Handled' is the past participle and cannot form an attributive compound in front of a noun. Modifying a noun requires a present participle or a derived adjective, not a past one.
• D) handler'Data-handler' would name a person, and the clause is about a written statement that precedes a study rather than about an individual. Nothing in the sentence refers to anyone who processes data.

Respuesta correcta: D) had

• A) hasIncorrect. The sentence refers to a past sequence, requiring the past perfect in inversion.
• B) wasIncorrect. 'Was' does not fit the past perfect structure required by 'Hardly'.
• C) didIncorrect. 'Did' would require the base form of the verb, not the past participle 'been'.
• D) hadCorrect. 'Hardly had...' is a classic C1 inversion structure used for sequential events.

Respuesta correcta: D) The current strategy is directed towards the wrong objective.

• A) They are literally looking for something in the trees of Cartagena.Incorrect. This is a literal and incorrect interpretation of the idiom.
• B) The approach is too noisy and aggressive.Incorrect. The idiom relates to direction/objective, not volume or attitude.
• C) A new environmental project involving trees should be started.Incorrect. This misinterprets the figurative meaning of the phrase.
• D) The current strategy is directed towards the wrong objective.Correct. This idiom means to follow a wrong line of thought or course of action.

Respuesta correcta: B) To watch and check the temperature regularly.

• A) To put one eye near the microscope all day.This is a literal reading of 'eye'. The supervisor is asking for attention, not a physical position.
• B) To watch and check the temperature regularly.'Keep an eye on' means to watch something carefully; the sensitive cultures explain why the temperature must be checked.
• C) To change the temperature as much as possible.Sensitive cultures need stable conditions, and the idiom refers to watching, not changing.
• D) To travel to the conference in Cali.The supervisor is the one going to the conference; the assistant must stay and watch the lab.

Respuesta correcta: D) The event is very rare.

• A) The eclipse can only be seen when the Moon is blue.This is a literal reading. 'Once in a blue moon' does not refer to the colour of the Moon.
• B) The eclipse happens every month.If it happened every month, there would be no reason for the whole team to work that day.
• C) The observatory will be closed during the eclipse.The whole team will be working, so the observatory will be open and active.
• D) The event is very rare.'Once in a blue moon' means very rarely; the rarity explains why the whole team will work on that special day.

Respuesta correcta: D) There were no samples left to repeat the experiment.

• A) The samples ran away from the laboratory.This reads 'ran' literally. Samples cannot move; 'run out of' is a phrasal verb about quantity.
• B) The researchers had too many samples to analyse.This is the opposite: they had none left.
• C) The experiment was repeated many times.The researcher says they could not repeat the experiment.
• D) There were no samples left to repeat the experiment.'Run out of' means to use all of something; without samples, the experiment could not be repeated, so the results are not final.