Question

The teacher said, "The earth is round like a ball.'
(Change the narration)​

Answer 1

Explanation:

The boll is round like a earth, said the teacher

Answer 2

The teacher said, "The earth is round like a ball.'

(Change the narration)

Answer:

The teacher said that the earth is round like a ball.

• As the given sentence is the universal truth so the tense doesn't change.

• If Reporting speech has Universal Truth or Habitual fact then there is no  change in the Tense.

One more example:

The teacher said, “The Earth moves around the Sun”.

The teacher said that the Earth moves around the Sun.