He was so busy that he couldn't go to the concert.（改成同义句)顺便提一下：Rose knows something about the matter.（改为否定句）He is an American child.(改为复数形式)He was so busy that he couldn't go to the concert.（改成同义句)He was_________busy____________go to the concert.
问题描述：
He was so busy that he couldn't go to the concert.（改成同义句)
顺便提一下：Rose knows something about the matter.（改为否定句）
He is an American child.(改为复数形式)
He was so busy that he couldn't go to the concert.（改成同义句)He was_________busy____________go to the concert.
答
He was too busy to go to the concert.
Rose doesn't know anything about the matter.
第三句复数形式？不改变主语吗？
答
HE can not go to the concert because he is very busy.
答
He couldn't go to the concert as he was so busy.
Rose doesn't know anything about the matter.
They are American children.
答
He was too busy to go to the concert
Rose doesn't know anything bout the matter
They are Amerucan children[child=chilren]