题目

Tom comes from Australia. He is now staying in Beijing with his family. Every day he gets up at about six thirty and has breakfast at seven o'clock. Then he leaves home at seven fifteen. He gets to school at seven forty-five. His first class begins at eight. There are four lessons in the morning. Morning classes are over at eleven fifty，and he has lunch ten minutes later.Afternoon classes begin at one thirty. There are two lessons in the afternoon. They are over at three ten. Tom stays at school for another hour to play games, and he gets home at about four thirty.Tom usually has dinner at s已知a＞0，b＞0，不等式-b＜1x＜a的解集是______．