Part I of this book provides general information about the TOEFLtest, Part II gives you an analysis of the various sections on the exam. Part III provides more detailed information about how to succeed on the different sections of the test. Part IV con-tains practice tests and the answers and explanations for the questions they contain. | Part V EOg flt A1 LT geomsi peae TeStTai Lieu Du Hoc at Passage 3 Lightning has been a mystery since early times. People of ancient civilizations believed angry gods threw lightning bolts from the sky. Nobody understood that lightning resulted from electricity until Ben Franklin flew a kite with a key dangling from the string and it was struck by lightning. In current times it is known that lightning has a very scientific cause. Generally within a storm cloud friction from water and iceladen clouds creates a negative charge at the bottom of the cloud. When that charge grows too great for the air to hold it back it is united with a positive charge from the Earth creating a channel of electricity that flows between the two points. The charge remains invisible as it moves towards the ground until it meets the charge rising from the ground. Once they meet a fifty thousand degree current superheats the air around the channel resulting in an explosion of sound known as thunder. In fact very recently it has been discovered that occasionally the positive charges appear at the bottom of the cloud which are then met by negative charges from earth. Florida leads the nation in lightning deaths. Approximately ten people die each year in Florida from lightning which surpasses the number of deaths caused by the winds of other weather events such as tornados and hurricanes. Lightning is much harder to forecast than a storm. Forecasters can indicate when a storm is likely to produce lightning but there is no way to know when or where lightning will actually strike. It is known that it can actually strike up to 25 miles from the center of a storm which occurs when lightning originates under a cloud but travels horizontally for a time before turning towards earth. Thunder is only heard up to ten miles from where lightning strikes so it is possible to be struck by lightning without even realizing there is a storm in the area. Generally people are injured by .
