She said,"I must go home."变为间接引语时,must需要变吗?像She said,"I can swim."就变为 She said that she could swim.把can变为了could

She said,"I must go home."变为间接引语时,must需要变吗?
像She said,"I can swim."就变为 She said that she could swim.
把can变为了could

,must不需要变,因为它没有过去式

不需要变的

要变，变成had to

不用，must没有过去时态