A — 6: Why is the Channel Tunnel considered to be a great engineering achievement?
B — 2: Why didn’t the British support the first project of the Channel Tunnel?
C — 7: What was the most difficult task in constructing the Channel Tunnel?
D — 1: What other necessary things had to be done to start operating the Channel Tunnel?
E — 3: How many tunnels does the project actually contain?
F — 5: What are the possible ways for a passenger to travel through the Channel tunnel?