71. The main purpose of the passage is to _________.
A.
show how useful the book is. B, explain
what creativity
C.
discuss how one can be creative D. tell what reaching aims at
E
A
new eight-kilometer road is under construction that links the port area with
motorway system. It is expected to carry 20,000 trucks and cars a day, which
greatly reduces the overcrowded traffic in the center of the city. As part of
the project, two four-kilometer road tunnels are being built below the central
area of the city, one for traffic to the north and the other for the traffic to
the south. The two tunnels are about 20 meters below the surface and are 12
meters wide, providing for two lanes of traffic in each direction.
In the upper part of the tunnel two
air-conditioning pipes remove the waste gas of trucks and cars and keep the
quality of air inside the tunnel. The lighting is at the top of the tunnel,
practically at its highest point. There will also be electric signs at frequent
intervals. They show traffic conditions ahead and can be seen clearly by
drivers. The wall is made up of four main elements, which include a
waterproofing covering and, on the inside of the tunnel, a concrete lining.
Each tunnel is roughly round and the
lower part of the tunnel is somewhat flat. The surface of the road lies on the
base, which is made of concrete and steel. The drainage system, just below the
road surface on one side, removes any extra liquid, particularly water. In the
event of fire, the fire main, which is made of steel, pipes water to many fire
hydrant stations at regular intervals along the length of the tunnel. The fire
main is at the side of the tunnel and at the level of the road surface. Other
systems in the tunnel will include emergency phones.