Water,________seems so simple and common, is___________makes life_________.
Children in the countryside can receive education ________ free since last year.
--- I can’t find Xiao Ping. Where did you see him this morning?--- In the reading room _________ he often studies in.
I regret _________ going on a holiday to France because of the bad weather last week.
All __________ can be done has been done.
--- What do you think of the film Schindler’s List? --- This is the best film _______ I have ever seen.