Choose the correct heading for each paragraph.
What can lift roofs from buildings and sweep houses into the air? Tornadoes can! Tornadoes come in many
sizes. Sometornadoes are only a few feet across. Others are more thanamile wide. Some tornadoes touch
down for a short time. Others travel for hundreds of miles.
A. Bad effects of tornadoes
B. Where tornadoes often form
C. Introduction to tornadoes
D. How tornadoes form
Why do tornadoes happen? Scientists are not sure. Tornadoes come from giant thunderstorms called supercells. A
supercell happens when warm, moist air rises to mix with cold, dry air. The mixing of cold and warm air cause
the air to spin. The spinning wind turns into a cloud in a funnel shape. As the cloud turns, the wind become
stronger. When the funnel cloud touches the ground, it is a tornado.
A. Measuring tornadoes
B. How tornadoes form
C. Bad effects of tornadoes
D. Tornado safety
3. Scientists have a way to measure the strength oftornadoes. They look at the harm caused by a tornado.
They use the amountofharm to estimate the wind speed. They use aspecial scale called the EF Scale. The EF
Scale measures the strength of the tornado.
A. Tornado safety
B. Where tornadoes often form
C. Bad effects of tornadoes
D. Measuring tornadoes
4. Tornadoes may be hard to measure, but scientists haveagood idea where they will strike. It's true that a
tornado can hit anywhere in the world at any time. Most tornadoes happen in the central part of the United
States. This area is called Tornado Alley.