题目内容
把下面句子合并成一句。
The old Olympic Games could date back to 776 BC．The modern games come from it．
The letter is from my uncle．I received it yesterday．
The teacher saw what happened．He was standing nearby．
The girl is not here now．She told me the news．
This is the tree．He was climbing it yesterday．
Do not drink water．It has not been boiled．
