请用英语写出下列句子的同义句
问题描述：
请用英语写出下列句子的同义句
1.It is two weeks since he left London
2.You must take care of yourself and keep healthy
3.The problem is so difficult that I can' t finish in on time
4.We spent twenty minutes cleaning the room yesterday
5.Chocolate is my favorite
答
He has been away from London for 2 weeks.
You must look after yourself.
The problem is too difficult for me to finish on time.
It took us twenty minutes to clean the room yesterday.
I like C best