The following tunnels were constructed in different countries for different purposes : 1. Emperor Claudius built the first Roman tunnel 2. The first highway tunnel was constructed in Hungary 3. The first underground railway tunnel was constructed in Great Britain 4. The first navigational tunnel was constructed in France. The correct chronological development of these tunnels is:
The following operations are generally employed for tunnelling in hard rock. 1. Removing ground water, 2. Loading holes and firing the explosive 3. Setting up and drilling 4. Grouting and lining 5. Removing muck 6. Ventilation and removing explosion dust The correct sequence is :