______ medicine works in a human body is a question _______ not everyone can understand fully.
---- What do you think of Andrew? ---- There are some things that are not easy to ______ and his coldness is one.
People usually turn on the radio to listen to evergreen songs, which _____ them of their past.
On the ground _______ the man, his face as white as a sheet of paper.
Well-mannered children have usually been properly ________ up by their parents.
We decided not to climb the mountains as it was raining ________ .