VI. Complete the text with the words below:

westbound, authority, tubes, vehicles, motor, conditions, vehicular, lanes

The Lincoln Tunnel, also used by motor__(1)__, provides a link between 38th Street in midtown Manhattan and Weehawken, N.J. The tunnel, operated by the Port __(2)__ of New York and New Jersey, is the only three-tube underwater __(3)__ tunnel in the world. Two of its __(4)__ are over 8,000 feet (2,400 meters) long, and the third is about 7,500 feet (2,290 meters) long. Each tube has two __(5)__ for vehicular traffic. The center tube, used for eastbound, __(6)__ , or two-way traffic as __(7)__ require, opened in 1937. The north tube, for westbound traffic, opened in 1945. The south tube, used for eastbound traffic, opened in 1957.

VII. What plan of the text The Mersey Tunnel is better? Why?

1. the Mersey Tunnel 2.engineering achievement 3. headings 4. ventilation 5.communication difficulties

1. basic information 2. the construction of the tunnel 3. the system of ventilation 4. the solution of communication difficulties

1. the famous Tunnel 2. the process and stages of construction 3. the problem of ventilation 4. the completion of the tunnel

Text 2: Central Artery/Tunnel Project (Big Dig)

The tunnel is called Big Dig. Why? Give your ideas

Some call the Central Artery/Tunnel Project in Boston, Massachusetts, the "largest, most complex and technologically challenging highway project in American history." Others consider it one of the most expensive engineering projects of all time. Locals simply call it the "Big Dig." The tunnel is eight lanes wide, 3.5 miles long, and completely buried beneath a major highway and dozens of glass-and-steel skyscrapers in Boston’s bustling financial district. What does it take to dig a tunnel like this? A lot of hard work and a handful of engineering tricks.

Today, engineers use special excavating equipment, called "clamshell excavators," that work well in confined spaces like downtown Boston. These special machines carve narrow trenches -- about three feet wide and up to 120 feet deep -- down to bedrock. In Boston, engineers are pumping liquid slurry (clay mixed with water) into the trenches to keep the surrounding dirt from caving in.

Huge reinforcing steel beams are lowered into the soupy trenches, and concrete is pumped into the mix. Concrete is heavier than slurry, so it displaces the clay-water mix. The side-by-side concrete-and-steel panels form the walls of the tunnel, which will allow workers to remove more than three miles of dirt beneath the city. As if tunneling beneath a city isn’t hard enough, the soil beneath Boston is actually landfill -- it’s very loose and soggy. Engineers had to devise a few tricks to keep the soggy soil from collapsing. Their solution: freezing the soil!

Engineers pump very cold saltwater through a web of pipes beneath the city streets. The cold pipes draw heat out of the soil little by little. Once frozen, the soil can be excavated without sinking. Engineers also inject glue, or grout, into pores in the ground to make the soil stronger and less spongy during tunnel construction.

Fast Facts:

1. The project will excavate a total of 15 million cubic yards of dirt, enough to fill Foxboro Stadium -- where the New England Patriots football and Revolution soccer teams play -- 15 times.

2. Reinforcing steel used in the project would make a one-inch steel bar long enough to wrap once around the Earth at the equator.

3. Moving all the dirt in the tunnel will take more than 541,000 truckloads. If all those trucks were lined up end to end, they'd stretch 4,612 miles. That's the same distance from Boston, Massachusetts, to Brasilia, the capital of Brazil.

4. The tunnel will emerge next to the FleetCenter, home of the Boston Bruins hockey team, and will cross the Charles River under the widest cable-stayed bridge in the world, the Charles River Bridge.

COMPREHENSION CHECK