设$\overrightarrow{a},\overrightarrow{b}$是单位向量，则“$\overrightarrow{a}·\overrightarrow{b}=1$”是“$\overrightarrow{a}=\overrightarrow{b}$”的

    Earthquakes may take place anywhere on the Earth's surface.1,they are most probably to happen near mountains.

    During an earthquake,the Earth's surface shakes.Houses fall,people are killed or injured,and2wholecities are destroyed.

    But we can do something to protect3against earthquakes,Scientists have made maps4the “earthquake belt”.In the belts,earthquakes are likely to happen.In these areas we can build 5houses to resist(抵抗）earthquake shocks.

    In the future,scientists will be able to predict exactly6earthquakes will take place.Then they can tell people to take measures.Thus lives can be saved and damage（损失）can be 7.