, 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. 72. Each of the tunnels under construction is _____. A. eight kilometers long and twenty meters wide B. eight kilometers long and six meters wide C. four kilometers long and twenty meters wide D. four kilometers long and six meters wide 73. Which part of the tunnel in the diagram is used to pipe out extra water? A. 1 B. 3 C. 5 D 6 75. The passage is mainly about _____. A. the construction of a road B. the design of a road C. the construction of two tunnels D.the design of two tunnels 老师可以读解一下吗不懂.......