The word tornado is from the Spanish word tronada, which means"thunderstorm". It is a violent, dangerous, rotating column of air which
is in contact with both the surface of the earth and a cumulonimbus
cloud. Cumulonimbus cloud is a type of cloud that is tall, dense, and
involved in thunderstorms and other intense weather. It is a result of
atmospheric instability,
Tornadoes come in many sizes but are typically in the form of a
visible condensation funnel. It is a funnel-shaped cloud of condensed
water droplets, associated with a rotating column of wind and
extending form the base of a cloud. This funnel's narrow end touches
the earth and is often encircled by a cloud of debris and dust. Most
tornadoes have wind speeds, between 64 km/h and 179 kmfh.
Although tornadoes have been observed on every continent except
Antarctica most occur in the United States. They also commonly occur
in Southern Canada, South Central and Eastern Asia, East Central
South America.
8. Who probably writes the text?
A. A reporter
B. A scientist
C. A student
D. A historian​