怎么把下面句子变成间接引语1.Sandra asked her friend how she could solve t

怎么把下面句子变成间接引语
1.Sandra asked her friend how she could solve the problem
2.“I'll have to stay in the lab until tomorrow”(the next day)
3.“I'm going to write a report next week.”(the next week)
4.“I watched a very interesting TV programme yesterday.”(the day before)
如果可以的话最好告诉我原理是什么在这里谢谢各位了