______ ______(平均)，there are 800 tornadoes in the US each year, ________(cause) about 80 _______(die) and 1500 _______(injure). The worst tornado ______ _____ ______(史上最严重飓风) ______(occur) in 1925, _______(affect) three US states: Missouri, Illinois and Indiana. ____ ____ _____ it ended(到它结束时), more than 700 people _____ _____killed and 1700 had been ________(injure).

On average

causing

deaths

injuries

of all time

occurred

affecting

By the time

had been

injured