火车站台边缘处标有一条安全线，人必须站在安全线以外的位置候车。其原因是火车急速驶过车站时，安全线与列车间的空气流速____ ，压强____ （均选填“大”或“小”），易发生安全事故。

 对图中的自然现象解释正确的是（　　）

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下列句子中加横线词语使用正确的一项是（   ）

     The children often play soccer in the garden(花园). Sometimes they break (打破).Mrs. Smith’s windows.  
One afternoon , Mrs. Smith is reading a newspaper at home. After a short time, she closes her eyes and goes to sleep. At that time a little boy knocks(敲) at the door. Mrs. Smith opens the door and asks, “Do you break my windows again（又一次）?” “Oh, no”, says the boy. “ Your windows are open this time and our soccer is in your room. Can I get it back, please?” 
根据短文内容，选择正确答案。