【单选题】Insomnia can be traced to many different reasons, but what is_____(23)to many sufferers is their inability to relax fully and 'switch the mind_____(24)'.
【单选题】The sufferer of insomnia can relax themselves before sleeping in the following ways EXCEPT ______.
C.
changing sleeping habits
【判断题】含湿量d是指每千克空气所含有水蒸气的重量。
【单选题】Which type of insomnia is regarded as the cause of jet lag?
【简答题】抽样的类型主要分为( )和( )两大类。
【判断题】概率抽样法的类型主要有任意抽样、判断抽样、配额抽样。
【单选题】Which type of insomnia is regarded as the most serious?
【判断题】含湿量 d 是指每千克空气所含有水蒸气的重量。( X )