battery—A device that stores
electricity.

carbon dioxide—One of the
gases produced by burning fuels
like gasoline.

diesel fuel—A type of fuel made
from oil. It is commonly used in
large vehicles such as trucks and
locomotives. Some cars use it.

electric motor—A machine that
uses electricity to produce a
turning action. This action can
turn the wheels of a car.

ethanol—A type of alcohol often
used as a fuel. It is usually made
from plants or from oil.

fuel cell—A device that uses a
reaction between two substances
to make electricity. Usually one of
the substances is hydrogen.

full hybrid—A hybrid car in which
the electric motor can drive the
wheels by itself.

generator—A machine that
uses a turning action to produce
electricity.

global warming—A gradual
warming of Earth’s climate. Many
scientists think that the burning of
fuels like gasoline helps cause it.

internal-combustion engine—An
engine that burns fuel inside itself
in order to produce power.

mild hybrid—A hybrid car in which
the electric motor usually just assists
the internal-combustion engine.

moped—A small motorbike with
pedals, which can be used along
with the engine to make the bike
go. The name comes from “motor”
and “pedal.”

pollution—Harmful or dangerous
substances that are put into the
environment.

renewable resource—A resource,
such as a source of energy, that never
gets used up. Energy sources such as
sunlight and wind are renewable.

smog—A type of air pollution found
in some big cities. One cause is the
burning of fuel by cars. The word
comes from “smoke” and “fog.”

turbine—A machine with a turning
action that can make electricity or
power vehicle wheels.

vehicle—Something that carries
people and things around. Cars,
buses, and trucks are examples
of vehicles.