网友回答：
the main cause of (某种现象) is due to (最主要原因). it is high time that something were done upon it. for one thing，话题作文， there are more and more (某种现象) in (某种场合). it is estimated that (相关数据). why have there been so many (某种现象)? maybe the reasons can be listed a
温馨提醒：随时光变迁，文中所陈述观点；准确性、难免有所变动，因此文中观点仅供参考。
