Question

what inference can you make about the people who saw pictures of the crystal palace?
passage detail
\people were impressed by the pictures of the crystal palace\ in the newspapers.
what you know
i am often amazed when i look at something new and interesting for the first time.
inference
people had never seen a giant building made of glass before.
people were expecting to see the displays on a short walk.
people thought the building would take longer to design.

Explanation:

Combine the passage detail that people were impressed by the Crystal Palace pictures with the prior knowledge that first-time exposure to new, interesting things causes amazement. The only option that connects this is the idea that people had never seen such a unique glass building before, which would explain their impressed reaction.

Answer:

People had never seen a giant building made of glass before.