Meaning: 'Fed' means to supply or provide something, in this case, the recordings to a computer program for analysis.

Wrong options:

• delivered: 'Delivered' implies a physical transfer of items, which does not fit the context of inputting data into a program.
• parcelled: 'Parcelled' suggests packaging items, which is not relevant to the context of data processing.
• pushed: 'Pushed' typically refers to a physical action and does not accurately describe the act of inputting data into a computer.

Correct answer: evidence

Explanation: The word 'evidence' is appropriate here as it refers to data or information that supports a claim, fitting grammatically and contextually with the sentence discussing findings from the experiment.

Meaning: 'Evidence' means information or facts that help to prove something, in this case, supporting the idea of a common ancestor among species.

Wrong options:

• grounds: 'Grounds' refers to reasons or basis for a belief, which does not fit as well in this context as it is less specific than 'evidence'.
• conclusions: 'Conclusions' implies final judgments or decisions based on evidence, but does not directly refer to the supporting data itself.
• testimonies: 'Testimonies' refers to statements made by witnesses, which is not relevant in the context of scientific findings.

Correct answer: evolved

Explanation: The verb 'evolved' is the correct choice as it is in the simple past tense, indicating a completed action that aligns with the context of discussing the development of laughter over time.

Meaning: 'Evolved' means to develop gradually, especially from a simple to a more complex form, which fits the context of primate laughter changing over time.

Wrong options:

• will evolve: 'Will evolve' suggests a future action, which does not match the context of discussing past changes in laughter.
• have been evolved: 'Have been evolved' is grammatically incorrect as it implies a passive voice that does not fit the intended meaning.
• were evolved: 'Were evolved' incorrectly suggests a passive construction that is not appropriate for this context.

Correct answer: from

Explanation: The preposition 'from' is the correct choice as it indicates the point of origin, fitting grammatically and contextually in the sentence about the split from a common ancestor.

Meaning: 'From' indicates the source or starting point of something, in this case, the common ancestor shared with chimps.

Wrong options:

• into: 'Into' suggests movement towards the inside of something, which does not fit the context of separation from a common ancestor.
• off: 'Off' implies a physical detachment, which is not the correct preposition to describe the evolutionary split.
• in: 'In' suggests being inside something, which does not accurately convey the idea of separation from a common ancestor.