I was impressed ____ subways my first time in Europe. Which word completes the sentence?

• A. By
• B. With
• C. At
• D. On

Answer: (A)

The main idea here is how we connect the feeling of being impressed to what caused it. When you want to say what produced the impression, the natural choice is by. So, I was impressed by the subways captures that the subways themselves were the source of your impression during your first visit to Europe. Using with would shift the nuance toward your satisfaction with the subways rather than what inspired the feeling, and at or on don’t fit the sense of a source of impression in this sentence. A natural way to hear it is that the subways impressed you, i.e., they were impressive to you.