People lived in caves many,many years ago改同义句
还有:
1.He solved the problem in a flash改同义句
2.It took me an hour to get there改同义句
3.Why not have some coffee改同义句
4.I am sure of his success改同义句
5.He didn't answer my letter改同义句
6.Peter interrupted me改同义句
7.Hurry up,otherwise,we 'll be late.改同义句
8.We will use the laser beam to melt the bars改同义句