Rearrange the following sentences to form a coherent paragraph: 1. It is a process that involves the systematic and objective investigation of a subject to discover new facts or to confirm existing ones. 2. Research is a foundational pillar of academic and scientific progress. 3. This can be either theoretical, aiming to expand knowledge, or applied, seeking to solve a practical problem. 4. The findings of this investigation are then documented and peer-reviewed to ensure validity and credibility.

Correct — A. Find the sentence that can stand first. Sentence 2 names its subject outright: 'Research is a foundational pillar of academic and scientific progress.'

The rest lean back: 1 opens with It, 3 with This, and 4 with 'The findings of this investigation'. Each needs something earlier to point to.

Sentence 1 defines research as a process of systematic investigation.
Sentence 3 classifies it as theoretical or applied.
Sentence 4, marked by then, closes with the findings → 2, 1, 3, 4, option (a).

Why the others are wrong

• (b)
  1, 2, 4, 3 — Opens with It is a process — an 'It' with nothing before it to refer to. Research is named only in sentence 2, so 2 has to come first.
• (c)
  4, 3, 2, 1 — Opens with 'The findings of this investigation', which points back to an investigation not yet mentioned, and pushes the topic sentence to third place.
• (d)
  3, 4, 1, 2 — Opens with This can be, a pronoun with no antecedent, and saves the topic sentence, 'Research is a foundational pillar', for the very end.

A jumble held together by reference words is solved from its opener. A sentence that begins It or This referring back, or 'the … of this X', points to something earlier, so it cannot open the paragraph.

Once the opener is fixed, follow the chain: each pronoun must find its noun in an earlier sentence, and time words such as then mark the later stages.

Here the chain runs topic (2), definition (1), types (3), next stage (4).

Key facts

• It or This referring back to an earlier noun cannot begin a paragraph.
• In this jumble, sentence 2 alone names research, the subject that It, This and 'this investigation' refer to.
• Then marks a later stage: sentence 4's documenting and peer review follows the investigation described in sentence 1.

Common traps

• Starting with sentence 1 because it reads like a definition — its 'It' needs research named first.
• Taking 'The findings of this investigation' as an opener because it sounds like a heading — 'this' points back.

No directly related past PYQ was found.