CITIES by Kathleen M. Reilly

Author:Kathleen M. Reilly
Language: eng
Format: epub
Publisher: Nomad Press
Published: 2014-04-19T04:00:00+00:00

ENGINEERS ARE ALWAYS TRYING TO THINK OF NEW DESIGNS TO HELP SAVE ELECTRICITY.

DOWN UNDER

The subway isn’t the only part of the city’s infrastructure that’s hidden under your feet. Cables for electricity and telephones and supply lines for gas and water all can be run underground.

There’s a benefit to running them underground instead of above ground. Underground cables and supply lines don’t interfere with buildings, trees, or transportation such as overhead lines sometimes can. They’re also less affected by bad weather—fallen tree limbs don’t break underground wires or pipes. They also are hidden, so they don’t make the scenery look unattractive!

There are some downsides, though. It costs more for cables and pipes to be run underground, since digging or drilling through rock takes more time and money than just stringing them up overhead. And it’s sometimes harder to fix breaks underground, too.

ACTIVITY

MAKE YOUR OWN

SUBWAY SYSTEM CROSS-SECTION MODEL

SUPPLIES

long foam rectangle

black construction paper

glue

various sizes of tubes and thin boxes, such as toothpaste boxes, straws, paper towel rolls

pencil and paper

yarn or string in different colors

markers or pens

Download

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