【专四听力满分突破】打雷

　　选材规范、标准演练;循序渐进、梯度提升;题量丰富、有效提高;技巧同步、一语中的;缩略速记，全面覆盖。 The cause of thunder has been a subject of discussion for a long time. In the third century BC, it was believed that 1.__________. However, the most accepted theory was developed in the 20th century. According to this theory, the bolts of lightning are very hot, 2.__________. When this high temperature bolt hits the surrounding air, there is 3.__________, sending out a shock wave, which we hear as a sound of explosion. Thus, thunder is caused 4.__________, near the stroke of lightning 5.____________. In case that you are outside during a thunderstorm, it is advisable to avoid open fields, beaches and lakes and also 6.__________. The safest way is to 7.__________ or stay in the car. 注意填横线处的短句，一行一个短句。

　　thunder is caused due to collision of clouds much hotter than the surface of the sun an instant expansion of the air due to rapid heating and cooling of the air Thunder can be dangerous stay away from tall trees get inside your home