把下列直接引语改为间接引语~

1.Robert said he was playing chess.
2.He said if Tom left.
3.The old man said where the post office was.
4.The teacher asked Tom to come there.
直接引语为祈使句时，改为间接引语，用带to的不定式表达。
5.Our science teacher said light travels faster than sound.
当直接引语是客观真理或自然现象,间接引语时态无须改变.
6.He said to me he would visit his uncle the next week.
next week 应转为the next / following week / month / year
7.Mike said he liked playing computer games very much.
8.Mike said to me he could sing and dance.

Robert said that he was playing chess.
He asked me whether Tom left.
The old man asked me where the post office was.
The teacher said that Tom came here.
Our science teacher said that light travels faster than sound.
He said that he would visit his uncle next week.
Mike said that he liked playing computer games very much.
Mike said that he could sing and dance.

1.Robert said that he was playing chess
2.He asked me whether Tom left.
3.The old man asked me where the post office was.
4.The teacher said that Tom came here
5.Our science teacher said that light travels faster than sound..
6.He said that he would visit his uncle next week.
7.Mike said that he liked playing computer games very much.
8.Mike said that he could sing and dance.