1．She asked me whether I had seen him the night before．（改成直接引语）

She asked, “___1_____ ____2____ see him ____3_____ ___4_____?”

2．My mother said to me: “Come back before 10．” （改成间接引语）

My mother ___5____ me ___6________7______ ___8______ before 10．

3．It was a very difficult period of my life．At that time I first met Nelson Mandela． （连成一定语从句）

_____9____ ____10______ ___11_______ I first met Nelson Mandela was a very difficult period of my life．

4．All hope was not lost．（写出同义句）

___12____ ____13____ ___14_____ was lost．

5．He prefers riding a bicycle to riding on a crowded bus．（（写出同义句）

____15____ __16_____ _____17____ on a crowded bus, he prefers to ride a bicycle．

6．We seemed to be able to see for miles at one point．（用it作形式主语改写）

___18_____ ___19_______ ___20_______ we were able to see for miles at one point．

按要求改写句子

Learning a theory without practice will be useless.（it作形式主语）

Learning a theory without practice will be useless.（it作形式主语）

Where he has gone is not known.（it作形式主语）