Question

question 1: form a chain connecting airports to planes:
pieces of knowledge

• airports
• baggage carousels
• hangars
• planes
• taxis
• terminals
• ticket agents

links

• airports ↔ hangars
• baggage carousels ↔ taxis
• hangars ↔ planes
• terminals ↔ ticket agents

Explanation:

1. Match the first link: airports connect to hangars (given link: airports ↔ hangars).
2. Match the second link: hangars connect to planes (given link: hangars ↔ planes).
3. Match the middle shared link: the remaining connection is terminals, which links to both hangars/planes and the next set (terminals ↔ ticket agents, but for this chain, terminals are the hub between the airport-hangar-plane chain and the other elements like taxis/baggage carousels via the given connections).

Answer:

1. airports → hangars
2. hangars → planes
3. terminals (connects to hangars/planes, and is the hub for baggage carousels, taxis, ticket agents)

Full chain structure:
airports → hangars → planes
↓
terminals
↓
baggage carousels ←→ taxis
↓
ticket agents