交替: to replace, alternately, in turn...
外国: foreign (country)...
惊动: to alarm, to startle, to disturb...
轮船: steamship, steamer, ocean liner, ship...
自愿: voluntary...
直视: to look straight at...
长远: long-term, long-range...
急救: first aid, emergency treatment...
天鹅: swan...
