Meaning: 'Crash' means to collide violently, especially in a way that causes damage, which is exactly what happens when two exoplanets collide.

Wrong options:

• explore: The verb 'explore' means to investigate or travel through an area, which does not fit the context of a collision, as it implies a peaceful action rather than a violent one.
• roam: 'Roam' suggests wandering or moving about without a fixed course, which is not relevant to the context of planets colliding, as it does not imply any impact or collision.
• implode: 'Implode' refers to collapsing inward violently, which does not accurately describe the interaction between two planets colliding; it suggests a different kind of event.

Correct answer: reinforcing

Explanation: The word 'reinforcing' fits contextually as it indicates that the warmth of the debris supports the idea that it was created recently due to the collision. It aligns with the grammatical structure, suggesting a causal relationship.

Meaning: 'Reinforcing' means to strengthen or support an idea or concept, indicating that the warmth of the debris confirms its recent formation.

Wrong options:

• sentencing: The word 'sentencing' relates to the legal context of declaring a punishment, which is irrelevant here and does not fit grammatically or contextually.
• forging: 'Forging' implies creating something through a process, often involving heat, but it does not convey the idea of confirming or supporting the recent formation of debris as 'reinforcing' does.
• conducing: 'Conducing' means leading to a result, which does not fit the context of confirming the recent creation of debris; it lacks the supportive connotation of 'reinforcing'.

Correct answer: hints

Explanation: The word 'hints' fits grammatically as a noun that suggests a clue or indication, which aligns with the context of the sentence discussing the initial evidence of the collision. It conveys the idea of subtle evidence rather than definitive proof.

Meaning: 'Hints' refers to small pieces of information or clues that suggest something, indicating that the observations provided initial evidence of the collision.

Wrong options:

• pints: The word 'pints' is a unit of measurement for liquid volume, which is irrelevant in this context and does not fit grammatically or contextually.
• faints: 'Faints' refers to losing consciousness, which does not relate to the context of providing evidence or clues about a collision.
• taints: 'Taints' means to contaminate or affect negatively, which does not fit the context of providing evidence; it suggests a negative connotation that is not appropriate here.

Correct answer: revealed

Explanation: The word 'revealed' fits grammatically as a verb indicating that something has been made known or disclosed, which aligns with the context of the sentence discussing new findings about the infrared brightness of the debris.

Meaning: 'Revealed' means to make something known or visible that was previously hidden, indicating that new information about the debris has come to light.

Wrong options:

• concealed: The word 'concealed' means to hide or keep something secret, which is the opposite of what is intended in this context, as the sentence discusses new findings.
• repealed: 'Repealed' refers to the revocation of a law or regulation, which is irrelevant in this context and does not fit grammatically or contextually.
• unsealed: 'Unsealed' means to open something that was sealed, which does not convey the idea of making new information known as effectively as 'revealed' does.