Tunnel lining segments e railway semaphore: o que têm em comum

1. Passo 1. Tunnel lining segments — faz parte de — Tunnelling shield. Lining segments installed behind the shield.
2. Passo 2. Tunnelling shield — é utilizado em — Tunnel. Shield tunnelling.
3. Passo 3. Tunnel — tem como parte — Street light. Lighting.
4. Passo 4. Street light — tem como parte — LED. LEDs.
5. Passo 5. LED — faz parte de — Traffic light. LEDs.
6. Passo 6. Traffic light — evoluiu de — Railway semaphore. The first traffic light was a railway-style semaphore.

Abrir Evothings