【单选题】以冰雪融水补给为主的河流,影响其流量的主要因素是
【单选题】在包装内填充一定比例的保护性气体如二氧化碳,氮气等的一种包装方法是( )包装。
【单选题】充气包装是在包装内充填一定比例的哪种气体( )
【简答题】狂犬病是人畜共患病,感染人后常伴发吞咽困难,表现为( )症。
【单选题】In order to reduce the increasing prices of vegetables, the toll (过路费) _____ if a truck carrying them passes through a toll station . [ ]
【判断题】A commode chair is used by a person who is too ill to get out of bed.