Directions: The first and the last sentences of a passage are numbered 1 and 6, respectively. The rest of the passage is split into four parts, named A, B, C and D. These four parts are not given in their proper order. Read the sentences and find out which of the following combinations is correct.

1. The Thames Tunnel is an underwater tunnel that was built beneath the Thames river in London between 1825 and 1843. A. However, the tunnel did become a major tourist destination, attracting about two million people a year, each of whom paid a penny to pass under the river. B. Although it was a triumph of civil engineering, the Thames Tunnel was not a financial success, with building costs far the exceeding initial estimates. C. It is 396 metres long and runs at a depth of 23 metres below the river surface. D. It was the first tunnel known to have been constructed successfully underneath a navigable river.
2. The construction of the Thames Tunnel showed that it was indeed possible to build underwater tunnels, despite the previous skepticism of many engineers.