<Li> They may appear nearly transparent until dust and debris are picked up or a cloud forms in the funnel . </Li> <Li> The average tornado moves Southwest to Northeast in the U.S., but tornadoes have been known to move in any direction . </Li> <Li> The average forward speed of a tornado is 30 miles per hour (48 km / h), but has varied from stationary to 70 mph (110 km / h). </Li> <Li> Tornadoes can also accompany tropical storms and hurricanes as they move onto land . </Li>

An effective method that can be used to survive a tornado is which of the following