阅读理解 All around us buildings shook．We decided to leave the town…We stopped once we had left the buildings behind us…The carts(马车)were moving on opposite directions, though the ground was perfectly flat, and they wouldn't stay in place even with their wheels blocked by stones． In addition, it seemed as though the sea was being sucked(吸)backwards, as if it were being pushed back by the shaking of the land．Certainly the shoreline moved outwards, and many sea animals were left on dry sand． Behind us were frightening dark clouds that opened up to show fire－like lightening, but bigger…Not long after that the cloud reached down to the ground and covered the sea．Now came the dust, though still thin．I looked back．A dense cloud appeared behind us, fol-lowing us like a flood pouring across the land．Then a darkness came that was not like a moonless or cloudy night, but more like being in a closed and unlighted room．You could hear women and children crying, men shouting．Some were calling for parents, others for children; they could only recognize them by their voices． Darkness and ashes came again, a great weight of them．We stood up and shook the ash off again and again, otherwise we would have been covered with it and crushed(压垮)by the weight． At last the cloud became thinner and thinner until it was no more than smoke or fog．Soon there was real daylight．The sight that met our still terrified eyes was a changed world, buried in ash like snow． －from Pliny's letter to a friend | 
