Complete the sentence: _____ first, nothing seemed very inspiring.

• A. In
• B. At
• C. On
• D. For

Answer: (B)

The main idea is using a common time-expression with first to mean the initial moment. When we want to talk about the starting point of an impression or situation, the natural collocation is “at first.” So, “At first, nothing seemed very inspiring” means that initially, at the beginning, nothing was inspiring.

Other prepositions don’t form the usual, natural phrase with first in this context; they would sound wrong or awkward here. For example, “in first” isn’t a standard way to refer to an initial moment, and “on first” isn’t used this way either. The expression “for the first time” exists, but that changes the meaning to something occurring for the first time, not describing the initial state of the situation.