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Photovoltaic cells are already a familiar sight on rooftops .

光伏电池早已成为屋顶上一道熟悉的风景线。

Girls scatter flowers from the rooftops .

姑娘们从屋顶撒下鲜花。

Those without gardens are increasingly using rooftops for their hives .

没有院子的城里人争先恐后地把屋顶变成蜂巢。

He 's a borderline schizophrenic who lurks in alleys and on rooftops .

他几近一个精神分裂者，潜伏在小巷中和屋顶上。

Survivors gathered on rooftops , frantically shouting or signaling for help .

幸存者聚集在屋顶，或疯狂喊叫，或打求救信号。