towards an analysis of errors made by university students ... - DSpace

suggests.
The importance of some ethnic characteristics
only in certain environments. The tall, thin shape of the
emerges
tribes
of Equatorial Africa, for example, is an advantage in their hot
climate: larger body surfaces in relation to body weight mean
efficient heat loss. In the Arctic, Eskimo body types are short,
heat preserving physiques. The dark pigment of the African skins
helps to protect against sunburn, but it also reduces Vitamin D
formed in the skin through exposure to the tropical sun. Racial
and genetic variation is clearly important to health, and doctors
must take this into account. But the majority of human sickness
affects all races, and the environmental forces in general outweigh
genetic
factors.
1.2. Speci fi c Texts
1.2.1. Texts translated by the Physics Group
TIP - Text number 1 - Physics
ELECTRIC
MOTORS
The electric motor is undoubtedly one of the most
helpful modern inventions. It is used in factories to drive
machinery for electric trains, for trolley-buses and to power
such everyday things as food mixers, polishers, vacuum cleaners,
record players, drills, sewing machines and electric
razors.
What makes this sort of motor so popular? One reason
is its efficiency. Figures show that it is much more efficient
than steam engines, or petrol engines. It is simple to work; it
does not shake, it is fairly silent; it has few moving
parts,
and therefore gets little wear and tear. It can be easily
started, speeded up, slowed down and stopped.
In fact for most