She __________ have left school, for her bike is still here.
In China, the number of cities is increasing______ development is recognized across the world.
In our class there are 46 students, ________ half wear glasses.
I wish to thank Professor Smith, without______ help I would never have got this far.
She brought with her three friends, none of_________ I had ever met before.
Many children, _________ parents are away working in big cities, are taken good care of in the village.