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or you _______________ (miss) the train.15. listen. someone ______________ ( knock ) at the door.16. be quiet. my father _____________ ( sleep ) in the bedroom.17. i _____________ ( go ) hiking with my friends last monday.18. my mother ___________ ( stay
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。
