Institution: Bangladesh Public Service Commission (BPSC) Exam: 18th BCS Question with Answer
Topic: Analogy (সাদৃশ্য বা অন্তর্মিল), Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The sentence discusses a shift in understanding regarding the Milky Way, suggesting that previously accepted facts have become uncertain. The phrase "seemed fairly well ___" indicates that the first blank should be filled with a word that conveys confidence or assurance about the knowledge of the Milky Way at that time. The best fit here is "established," as it implies that the facts were widely accepted and considered reliable.

The second blank, "come into ___," suggests that these previously established facts are now being scrutinized or doubted. The phrase "come into question" is commonly used to indicate that something previously accepted is now being challenged or debated, which aligns perfectly with the context of the sentence.

In contrast, the other options do not fit as well. "Diminished" and "disrepute," for example, imply a negative outcome that doesn’t match the context. "Determined" and "resolution" suggest a more permanent state of discovery rather than ongoing inquiry. Thus, "established" and "question" collectively convey the evolution of our understanding of the Milky Way effectively.