37.Lucid dreaming, the ability dreamers to become aware of and to control their dreams while dreaming, is the focus of some current psychological research.
1 used to mean a person or thing, when you do not know or say exactly which
There must be some reason for her behaviour.
Can you give me some idea of the cost?
2 used when you are talking about a person or thing that you do not know, remember, or understand, or when you think it does not matter Some guy called for you while you were gone.