The bird covered the distance in three minutes.时态为?助动词 对covered the distance 划线提问
up to now的同义词组是?He has begun his own private'telephone' service.时态为?助动词 否定句 一般疑问句 肯否回答 对his own private'telephone' service划线提问
He has begun his own private'telephone' service.时态为？He has begun his own private'telephone' service的助动词He has begun his own private'telephone' service的 否定句He has begun his own private'telephone' service的 一般疑问句 He has begun his own private'telephone' service的肯否回答 对his own private'telephone' service划线提问