The poor children ______ worry about ________ money to go to school.

Safety in school has been of great concern because of the frequent reports ________ students got injured or killed while in school. [ ]

－MrHarry, we want to hear what you think about the reform being carried out in our school.－OK, I ___ to that

The book was so interesting that he read it for four hours _______ he realized it.

His mouth is not big.（近义词）